It will run on the same OS as the iPod/iPhone, meaning the 100,000+ Apps in the App store will all work on the iPad. Sadly, as unlimited as the App store seems to be, this is in fact a bit limiting: software that runs on any 'normal' OS will not run on an iPad, making it more limited than a traditional laptop.
Sadly, the tablet does not seem quite as ground-breaking as it could have been. No camera, no multi-tasking (which means no web browser and e-mail app, no Pandora and web browser, no iTunes and iBooks). No word processor. It's still linked to the AT&T 3G network, which I think we've pretty much established is an excellent way to lose customers. AT&T cannot support the existing 3G demands from iPhone users, damaging its service to all customers. I shudder to think what an influx of iPad users will do to the network.
The best news for the publishing industry comes in the form of
Currently, the store plans to launch with e-book content from Hachette, S&S, Penguin, Macmillan and HarperCollins. Random House, you might notice, is suspiciously missing from the list. In a statement, however, Stuart Applebaum said, "Random House welcomes Apple's iPad and iBooks app and we look forward to our continuing conversations with them about how we might best work together." (from yesterday's PW announcement)
The iPad will run on the traditional e-Pub format, but it is still unclear if e-books obtained from outside the iBook store will work on the iPad as an e-reader (are you tired of all these vowels yet?). Technically, e-books in e-Pub work across various devices, including the Sony e-reader. Apple also has not clarified how it will address self-publishing (which Amazon offers for the Kindle).
The iPad will be available in March... expect a lot of buzz (and bashing) before then.