Sony is to Kindle as PC gaming is to consoles...
Able to more and do it better, but the masses are more interested saving time and money than the best experience.
Sony should drop the 6" line, for simplicity. After reading on a 7" reader, I don't think I can ever go back.
... Maybe the next Kindle will have a 7" screen. They'd have to drop that hideous keyboard for a touchscreen... If it was half the price, I'd have to go with the 7" Kindle4. But I'd miss the build quality and especially the superior firmware (PRS+ anyone?) of the PRS.
As far as the Sony having awful software comment, I've been reading on PRSs for 5 years and have never installed it!