users don't care
What the TouchPad firesale tells us is end users don't really care what OS is running if the price is right and they don't really care how big the relevant app market is if the price is low enough.
It's fun arguing the dev side of the tablet wars but the public see a consumer device and as long as it has a working browser, passable email and some chance of running apps, don't look much further than the price. Its already a commodity item from their POV. Hardly news, the ongoing sales of piss poor chinese phones tells us the buying public will buy anything cheap that looks superficially good enough.
That's why WebOS is largely irrelevant even if its not dead, the entire appeal was the sale price, the OS isn't a selling point. WebOS can live or die and the buying public won't even notice.