Congrats to Sony !
PS3 is very successful. I couldn't say if it's more or less successful than PS1, I'd say both are equally successful.
Now PS3 has the potential to sell even more in the years to come...
Like MikeB said, it's good to see a technically advanced product succeed. PS3 definitely helped Bluray succeed as a superior format even compared to the dead HDDVD.
Something the PC market wasn't able to achieve.
Nobody says there aren't more powerful PCs today, but they cost a lot more and Sony both has top level content AND advanced technology. PC market now lacks content... You've got a handful of 360 / PC games like Mass Effect 2 but otherwise, piracy definitely hurt this market contentwise.