[Kilfer]

Remember the scene where Peter tries to read into his mother's mind, while she's in a coma, and he's somehow mentally "blocked"? Now, there are many different possibilities (she blocked him on purpose maybe), but I think obviously we know that somehow Arthur had (Ahead of time) put some kind of "stopper" in her head so she couldn't do anything, or be seen.

Now, in the earlier episode, where they're in the near future, Peter tries to force his way into Sylar to take his ability, but is blocked, much nearly in just the same fashion.

It's my belief, that everything that has happened thus far, has helped the future they saw, come into play. The ONLY difference, is that present peter, has Sylar's ability, something future peter never had. It is also my belief that amongst the things going on in the present timeline rightn now, that Sylar kills Arthur, and ends up with his ability.