I'll be ordering one for sure. Anyone see any compelling reasons to wait for the 3G version?
As noted, this decision will depend mostly on where you will use your iPad the majority of the time. If this will be a living room device to take the place of your laptop when at home and relaxing, the WiFi version will probably do the job just fine.
If you are going to take this on the road and don't want to depend on finding a Starbucks or a friendly hotel, you'd better wait for the 3G version. You'll just be frustrated when you need Net access and can't find a free hot spot.
If you are in between, using it mostly at home, but sometimes you want to throw it in your backpack, you'll need to figure out just how important it will be to have that always-on access that 3G provides. I think the answer here comes down to whether you are an iPhone user or you can be satisfied as an iPod touch user. If the thought of just having an iPod touch bothers you, you need the 3G iPad.