In my personal opinion, Dr. Harrison Wells IS Barry from the future, and here's why. Now, we all know that there were TWO speedsters on the night of Barry's mother's murder; one yellow; one red. Based on that, we can already assume that Barry did in fact travel back to that night, along with our prospective Reverse Flash. The vortex of lightning is very obviously the two of them in conflict, one chasing after the other. So, considering that he's been given at least ten years to hone his abilities, Barry would then be approximately on par with the Reverse Flash seen in the finale in terms of speed and skill.
Now given that knowledge, one might come to the conclusion that there were only two options available for future Barry on the night of the murder: Save his mother, or save himself. He may be the fastest man alive, but he is definitely not fast enough to be in two places at once. Obviously, Barry's first instinct would be to save his mother; it's pretty much his entire reason for going back to the past. However, had Barry saved his mother, not only would that present the entire paradox issue, but young-young Barry may have very well been murdered by the Reverse Flash instead, resulting in the impossibility of him EVER saving his mother. As long as young-young Barry lives, future Barry essentially has an infinite number of attempts to rectify the past; a necessary, but traumatic decision that would haunt and guilt him for the rest of his days. This results in a darker, jaded perspective of everything for future Barry (allowing your own mother to die so that you can live would easily have that effect on anybody). So, it now becomes that much easier to understand why Dr. Harrison Wells would not only be secretive or willing to do whatever it takes (lies, murder, etc.) to ensure present Barry's safety and success, but also why he is so fixated on preparing Barry for the future (or the past, depending on how you look at it).
Now, assuming that YOU were in future Barry's position, with all the knowledge of the future and the events of the night which form his crucible (mother's murder), would you not do everything in your power to keep that knowledge from yourself? Consider this, had Dr. Harrison Wells, aka present-future Barry, directly told present Barry that he is in fact himself from the future, would that not put him in a position of endless questioning? But more than that, if present Barry found out that he allows his own mother to die, wouldn't he do EVERYTHING possible to prevent that future. So for obvious reasons, Dr. Harrison Wells keeps his true identity a secret from present Barry while working behind the scenes to ensure that Barry becomes the man he needs to be. Now, here is where things get interesting. Given the knowledge that Wells can't reveal himself as the future Flash, it becomes necessary for him to don the guise of the Man in the Yellow Suit (notice how I didn't call him the Reverse Flash).
The Reverse Flash, a man shrouded in mystery, is present Barry's white whale; but besides the speed, red lightning and yellow suit, present Barry knows absolutely nothing about him. This is something that Wells would be entirely conscious of because he had already experienced it. So, lets imagine for a moment that Wells revealed himself as present-future Flash immediately. This would give present Barry knowledge of the future, but more than that, what he becomes. This would lead present Barry to simply ASK Wells what he should do and how he should handle things; which would change the future entirely. So, knowing full well that he needs to get present Barry ready, but can't do so directly, Wells is faced with a dilemma. Fortunately, Barry (past, present and future) is incredibly intelligent and resourceful. Armed with the knowledge of his past and fitted with 24 years worth of skill and experience (remember, the newspaper reads the year 2024 and Wells has been in the past for 14 years), Wells has had basically a quarter century to plan, prepare, and pretty much have the knowledge of how EVERYTHING plays out until the year 2024. This is a phenomenal advantage on his end. So with that much time on your hands, especially being the FASTEST MAN ALIVE, Wells has had a lifetime to get creative in finding a way to get himself ready. Wells knows he can't just wear a red suit; there would be NO conflict there to motivate present Barry to become faster. Hence the yellow suit; present Barry's white whale. This would explain why all he did was taunt present Barry instead of trying to make his life miserable. Remember, that is the Reverse Flash's m.o. - he can't kill Barry, but he can sure as hell kill everyone that he loves. This explains why the Man in the Yellow Suit (present-future Flash/Wells) appears precisely when he does - to give present Barry a tangible enemy and not just the faded idea of one. Present Barry NEEDS a physical enemy, but more than that, he NEEDS to know that someone is faster than him. That's why Wells appears as the Man in the Yellow Suit - to give present Barry a REASON to be better. Wells is trying to covertly mentor him.
By demonstrating to present Barry how much faster he really is, it gives Wells the opportunity to motivate him - thus resulting in an even FASTER Flash by the time he needs to face off against the ACTUAL Reverse Flash (the same one who spared Eddie and beat Wells to a pulp). This explains why there appears to be two Reverse Flashes - one real, one disguised present-future Barry. That is why Wells appears in the yellow suit almost immediately before the true Reverse Flash makes his first REAL appearance - he knows that R.F. is in town. With the yellow suit, Wells is able to guide present Barry as he faces off against the true Reverse Flash. Moreover, this explains why Wells had the Flash ring and the creepy voice. If you had come from the future to make someone's life hell, you wouldn't disguise your voice, especially considering they have no idea who you are if you've traveled far enough back in time. Present Barry is able to vibrate his vocal cords in order to mask his voice, but only marginally - you can still hear a glint of present Barry's true voice. Now, given 24 years experience, would Barry seriously not have a greater degree of control over this skill? I highly doubt it. Hence the creepy voice - it's Barry's trick.
The real Reverse Flash would have no need to mask his voice because Barry doesn't know him. Only Wells. Barry and Wells also (however darker Wells may be) have pretty much the same personality and sense of humor, but more than that, THEY HAVE A SENSE OF HUMOR. A deranged villain would have a deranged sense of humor - like the Joker or Count Vertigo for example. They WOULD NOT change their name in a nod to H.G. Wells - that is a 100% Barry move. Not only that, but what is the coincidence that all of this would happen towards Christmas? What if appearing as the Man in the Yellow Suit is Wells' way of giving his younger self a gift - the man who Barry has been looking for his entire life (who cares if it's really Wells in disguise, Barry doesn't know that). That is why we see Wells at the end saying "Merry Christmas" in the creepy voice. He's wishing HIMSELF a merry Christmas very much in the same way that anybody alone and depressed during the holidays might.
Anyways, let me know what you think about my theories on [The Flash](series:1068303)!