i doubt it set that long after the wolverine so why would he suddenly age very quickly
it would be weird that storm looks young still and wolverine is going grey now, unless having his healing powers taken away in the wolverine is gonna have his ageing catch up to him, but we seen nothing to hint at that
i'd take it as a pinch of salt right now though, we didn't see Xaviers face either in one of the pictures
In all depends on how the story is done. For example, if it is per the comic, meaning that the Sentinals take over, over time, in the normal timeline, then yes, I agree with you that it is unlikely to be too much after X3, maybe even present time.
But the other way the story could play out is for us to start the movie in the normal timeline, again not too long after X3. Ororo, Kitty, Bobby, Piotr, Rogue and Logan would all be there. Something gets changed in the past, by either someone contacting the past or going to the past (I.E. Fitzroy or Nimrod per the cartoon storyline). When the past gets changed the future (or present) changes around everyone. Some who were just alive are now "slain". Now you could have an aged Wolverine as a loner yet to be caught, again similar to the comic book story. Some who were never part of the story now exist (Bishop and Blink). What the year is doesn't need to be disclosed, just that we are now in a new reality and things are different. Again, all very similar to the comic, but with some of the cartoon aspects.
This, of course, would lead to some having to go back in time (using Blink's powers) to right the past and fix the present (or future).
But whether Wolverine has some gray hair, per the comic book, is really a minor thing. The main point is that the leather jacket Hugh is wearing appears to be similar to what Wolverine is wearing on the comic book cover, meaning that it is from the Dystopian future and not from the 1973 past!