Honestly, they've not been all that good thus far.
For example, AFAIK very few have nice capacitive screens, I believe only the high end Archos ones do.
I suppose it really boils down to what you want to do with it and how urgently you need it.
Netbooks are really quite good for browsing in bed, on the toilet etc. I'll grant that the keyboard occasionally gets in the way when all you want to do is read an ebook, but the flexibility of having one, in my opinion outweighs the inconvenience of not. At the moment, I'm actually also coding on the bloody thing and designing some artwork. When I can code on a tablet, I'll buy one I reckon ;)
Wait a bit and see what happens, I would think.