Really? Have you read the 4E material or played it yet?
A little bit, when it first came out...
However.....
When 3.5 was announced, Cook got upset that they released it 2 years early. Not that they did a 3.5 edition, but that released it early. It was also his rant that revealed the 5 year dev & release cycle. This says that "3.5" was always planned. In that sense of things, it is quite likely that they do a 4.5 version.
As for moving anything closer to what 3e was, I'd say that that was doubtful. The whole move into the 4e style of rules was done to move things away from the 3.x rules (which had been released under the OGL) in order to move away from the OGL itself (hasbro's lawyers hated the hell out of the OGL).
I just cannot see them allowing the rules to move back towards something that they tried so hard to move away from. Not to mention the fact that moving towards 3.x will be seen as taking a step backwards, something any company is loathe to do.
Now, having said that, there is nothing to stop them from tweaking 4e to add in a better skill system or improving it in any number of other ways.
And just because I expect version 4.5 rather than version 5, it doesn't mean that I will be right.....
They just might go straight to version 5. Afterall, Mearls has been spouting about "what makes D&D" and other nostalgic stuff, and that could mean that they take the ruels and go back to basics, and rebuild it from the ground up, using updated versions of the original rules....
There are many strong possibilities about which way they may jump. Until there is a little bit more information, I'll stay with 4.5 being where they are heading and then update my opinion as more information is available.