It's basically the ultimate "access" machine. Just yesterday I used my phone as a dictionary, store, terminal to enterprise software, link to external contact database. (also made some phone calls) iPad would be similar. Lookup, lookup, lookup. Web browsing is covered under that, too.
One thing the iPad brings that any phone cannot is a level of professionalism. In the companies I deal with, using your phone during a meeting looks questionable, like you're fooling around. Using a tablet or laptop to do the exact same lookup of whatever would be ok. It's a little silly, but that's the vibe I get currently.
This is not to say everyone has use for it. I'm happy with the phone, I'm not in that many meetings.