I put a ZUM on my iPad 2 immediately, and never looked back. Didn't have any cracking issues. As with all of you I've been waiting for the revised version for the new iPad. Except that the unexpected happened - I'm kind of liking going without.
At home, most of the time the iPad sits in its Wedge-E. At work, it sits landscape on my desk with the SmartCover as a stand. But several times in the past week I've removed the SmartCover and held the iPad plain; I find the feel of the aluminum much nicer than that of the microfiber of a folded SmartCover, or the poly of a half-folded cover.
Perhaps I should scold myself for never trying it this way from the beginning, since it's using it as designed. I just need to figure out if my paranoia of scratches outweighs the desire of going plain. Not to mention retraining myself to realize the cover is no longer locked to the iPad.