I'll give it about a 1 in 3 chance that we'll see a camera built in. I think it's very possible that it's already there, but the software wasn't ready for prime time yet. We all know how Steve hates to show something that's not ready yet.
I'd give it about a 50/50 possibility that we'll see OS 4.0 on the iPad when it ships too. 4.0 might add multitasking capabilities for 3rd party apps (since we know that Apple apps like iPod can already multitask with other apps). The biggest visible change will probably be the ability to arrange icons on the device home page any way you want instead of just limiting you to a grid. Of course, they could do this without revving all the way to 4.0.
I also think we'll see some of the standard apps found on the iPhone and iPod Touch that were conspicuously absent at the announcement, enhanced and improved for the larger display and higher power. Weather will let you see live satellite photos, etc. Stocks will give for info and probably news headlines for your stocks, and we'll see a much more powerful calculator app.