Uh... anywways sticking with the thread title....
Online racing isn't going to be that fun honestly. While it seems like a welcome addition to the GT Seriers, have you ever played other online racing games like Live for Speed? This game uses some pretty complex lag prediction methods, UDP packets etc... so its pretty efficient, and the lag is pretty bad in some cases.
And Playonline doesn't have much experience in the online realm like X-Box does and such. Perfect example... Ive been playing Final Fantasy XI for a while now, and they didn't even bother to put up servers in the USA. So I mean unless u hear about servers going up in places other then Asia, I wouldn't hype it up so much. I was getting 100-500ms ping reply times during non peak hours, so I mean once GT4 is out you'll have a huge increase in in server load, and a decrease in quick ping reply, which means ur cars are gonna be jumping all over the place, or at least inaccurately placing ur car on the track which means valuable seconds lost
*shrug*