Thanks for this thread. Wasn't aware cases were going so quickly, as well. I didn't expect that.
I've pre-ordered the 3G 64GB. I was really quite sure I wanted the case, too. The functionality of it as a frame and a typing platform seems ideal to me. Had heard some mixed things about the material and the quality, so I wanted to see it in person first. However, since I'm going on a 2 month business trip to Seoul in May, I don't want to risk them being on back order when I walk into the store in mid-April. (I'm out of the country now, too. Bonus is the 3G wait doesn't really affect me that much.) Bottom line, I went ahead and ordered the case separately. Figure I can always return it or sell it.
Now I'm just praying that both iPad 3G and case are not delayed for any reason.