They were already slashing prices on the Android tablets before HP made their move. Staples had their $100 off any tablet promo and just recently Acer slashed the price of the Iconia from $450 to $400 and most stores were offering a $100 GC on top of that for a net cost of $300. Amazon had a 20% off coupon for Amazon Visa cardholders that worked on a lot of tablets, pulling the net cost for the Iconia to just over $200.
So far, I believe the only Android tablet that's had any sort of success would be the Transformer, and even the interest in those has died down since the first couple months when supply was getting ramped up. I thought the Galaxy 10.1 would be the most popular Android tablet, but they're still getting outsold by Transformers on Amazon despite being newer to the market.
I'm curious who will actually continue to produce tablets a year or two from now. With the manufacturing costs, R&D, marketing, etc.. that goes into selling tablets, it's an accomplishment to simply not lose money on these.