That has a sort of sense, but cannibalizing their other titles in an entirely different genre is hilarious. Or would be if it failed spectacularly. Since its going to sell in droves I find that equal parts depressing and awesome. Depressing because no one is going to point out that they're varying at most a dozen ideas for the last decade, and awesome because it takes mad skillz to do that over and over again and still sell games by the millon.
Diablo 3 so far looks, and most likely will be essentially a remake of Diablo 2. It will even share its flaw of having graphics half a decade behind the times (seriously, Titan's Quest looks better or at least the same).