Maybe Sony SHOULD delay another half a year. I mean, it'd surely sucky to miss the 06 holiday season, and I have no idea what kind of games they could launch that'd actually bring in significant pocketchange during Q3 and Q4 06, but supposing they did wait to launch, it could be very interesting.
You hold off and set up another Killzone title, another GTA title, MGS4 and maybe even have Squenix set you up with one as well. Odds are they'll have a Jak title set, as well, and probably yet ANOTHER Tony Hawk game and another SOCOM. You wait til mid year 07 to release. Let all the steam die down from the 360 stuff. You release with your awesome library in the middle of the year at, say, $350. It's going to piss off MS, as I'm working under the assumption that they really are hoping to release Halo3 near the PS3 release date, and I can only imagine how much Xbox would rather hold off on Halo3 til the fall and not in mid summer. Then once november approaches, you drop the system price, so you've already got a good solid group of people that have bought it, but you'll still get the attention during the holidays. It could work, and that way, as Nintendo will probably delay the Revolution a bit as well if they feel that there's no hurry to compete with the 360 (and lets face it, I doubt nintendo cares nearly as much for their consoles as they do for their handhelds at this point), then it really just kills the steam that MS has built up by trying to take the bull by the horns.
It could backfire, as others have said, but it'd be interesting to say the least. What would add to the acceptance of a delay by Sony, as well, is if their software/hardware are continually built up, so that when they do launch, they can still offer their DVD-R attatchment and whatnot that they were toying with. With nintendo doing the same thing... could be interesting.
Not that I think it'll happen. I think the release dates will go on as they are now, with everyone releasing crappy games (for the most part) at launch and filling in the libraries later. This is a fairly high-stakes game these guys are playing and I doubt anyone has the balls to go out on any limbs when hundreds of millions of dollars are at stake.