Yep I definitely have considered that as well. Especially the possibility of RTS board games of some sort, as opposed to turn-based. I'm sure the Parker Bros would be well advised to make a Monopoly app.
I've got to admit, the board game idea for the ipad is pretty cool. In general, though, I'm not convinced I see the game market for the ipad being as large as it is on the iphone. A phone is in your pocket when you're on the bus, in the waiting room, or in the bathroom (you know you do it). These are perfect opportunities to pull out the device and play a game for a few minutes. I don't see people having as quick of access to the ipad or planning to bring it somewhere just to game on.
That being said, I'm guessing we can assume that the next flash sdk's ability to build for iPhone will extend to the iPad, in which case the games floodgates are going to open regardless.