Scribble
First Post
To the OP: Can you prove that 5th edition isn't around the corner?
I hate to break it to you but 4th edition in total hasn't lived up to what the designers thought it would. They set out to bring in hoards of new players along with the old and I'm afraid it backfired on them. No amount of tweaking and changing the current rules is going to bring back the masses.
Well I think the only ones who can prove anything one way o another are the WoTC folks... and they're sure as heck not going to say.

We can look at what's been happening for some ideas though.
They've said in the past they'd like to see the "core" 4e rules as being used similar to the MTG core rules. A small subset that can be expanded on and modified by future expansions without being totally rebuilt each time.
We're seeing this in action with things like Essentials and Gamma World.
Mr Mearls's posts lend more evidence to this idea. IE new entries into the game that change how you get to the table, but don't invalidate one another.
I think we're also seeing that WoTC learned that D&D like it or not is a lot of things to a lot of people, and if they don't market to those people it's seen essentially as WoTC saying that their view of what D&D is is invalid.
Editions seem to promote this. RThey cause strife, and a break in the "community."
If they can mold the urrent game the way they've been doing with Essentials and Gamma World et al, they can start opening the game up to account for a lot of different play styles.