With WWE making the decision to make all PPV's tri-branded and with various stars appearing on all brands (from time to time), added to the fact that a lot of WWE's top stars are out injured, the argument for WWE to go back to one major brand, holds much more weight.
I would love for WWE to go back to one major brand, as there are far too many stars on the roster; yet the seperated rosters are very light weight. Also, the titles have less meaning, due to there being so many. The ECW Title is hardly considered a World Title, leaving the WWE/World Titles. By puttting those titles together, the ME picture is much better, as is the prestige of the World Title.
The same can be said for the secondary titles. The US Title should be united with the IC title, going back to the former WWE midcard structure. The CW title and Women's titles would remain, and the Tag Division would be much better, as teams from all two/three brands would unite.
There is only one drawback I can think of with this move. That is, various wrestlers will have to be released. However, this won't be too big an issue, as they won't be top guys in the company, so it won't matter. Also, the issue with 'stars being even more burned out with the house show schedule' won't be any worse, as top stars are already overworked. But by this system, top stars could 'alternate' which shows they appear at.