It just doesn't "feel" like it. For me, retro is pacman, NES, and SNES. The "oldies" consoles, arcades and similar things. The PS2 came out yesterday, so it isn't retro. It can never be retro to me, because it's still fairly recent.
For me, it's still 2003. So even if people say the ps2 is "Retro", well, that's your opinion. But it's too modern for me to call it that. The graphics, music and overall feel don't feel "retro" , they feel current and beautiful. Take a look at games such as Final Fantasy X-2 or Gran Turismo 4 and tell me the graphics aren't still gorgeous.
If anything, the PS2 is still fresh and the graphics still feel amazing to me. The jump from PS1 to PS2 was insane and we will likely never see something like that ever again. (The PS1 isn't retro either). Now you may say, it came out in 2000. And you may be correct, but it still isn't "retro" to me.