Specifically 7" Android tablets. Even More specifically the Coby Kyros 7022. In a nutshell, I like it. For the price, I am perfectly happy with its utility. I would not have wanted to pay more than the slightly under $200 it costs, for what it does. But I also don't see more expensive tablets doing much of anything worth paying more for.
Basically, the niche tablets fall into now is that they are essentially low powered netbooks. The problem with this is that netbooks are already as low powered as is practical for most actual productive applications. But...
Tablets are really cool for surfing the web in bed. There portability makes them pretty nifty videogame machines, media devices, and that kind of stuff. I may get some use out of mine for reading PDFs as well, although I definitely prefer my ereader for actual book reading. Oh, and I just read a comic book on the tablet as well, and actually enjoyed it more than on my larger netbook screen. A 10' tablet, or even 12' (should one hit the market), might be better for that, however.
As kind of a back-up option for the netbook, the tablet is nice, too. I am typing this entry on mine. It's definitely clumsier than it would be on the netbook, even using a full sized USB keyboard, but it does get the job done.
The Kyros 7022 runs Android 2.3, BTW. I can see room for improvement, which presumably 3.0 and 3.1 have been. But again, a little clunky, but gets the job done.
The netbook I have is an Asus 1005p, BTW, and it is my main computer. It does enough, and is portable enough, and gets about 6-9 hours out of a charge. Since I don't do processor intensive stuff, it has been great for me so far. When I write I just hook it up to A USB mouse and keyboard and a bigger monitor (an LCD TV/DVD combo that serves triple duty in my household.)
This post has gotten long enough that my tablet is freaking out, so I'll stop here. Short post shorter - I like my new tablet, and think most people could get some use out of one, this brand or another. Especially writers who spend a lot of time online trying to learn new stuff.