There are certainly more than a thousand apps in the Google Market. Anyone claiming otherwise has not done his research.
I believe there is a tablet market outside the iPad, but how big it is remains to be seen. I like my Nook Color CM7 device, and would really like a 10 incher with a few more features. I know several people in Real Life that feel similarly, but who don't want an iPad for various good reasons. A net book isn't the answer in several of these situations. It's a case-by-case thing.
My use case for a tablet is something that I can lay flat on a table (like a paper notebook), write on with a stylus (like a pen), and have the writing converted into computer text -- basically, let me write my novel "on paper" into Google Docs or something similar. Yes, there are laptops that have detachable screens, but as far as I can tell, they cost far more than a new tablet.
Now I just need the HTC stylus tablet to come out and live up to the marketing blurbs.
I would like to add to this discussion that just because YOU cannot see a need for a tablet does not mean OTHER people do not. Haven't we already gone through that with smartphones and eReaders and everything else???