socket 775 outdated?

Should i think of buying a 1366?

Yes and no. Core i5 is coming out later this year, and doesn't use the 1366 socket. So, it is totally up to you. Personally, these days, you either build a Core i7 setup, or you go AMD Phenom II, because of performance. Core2 vs Phenom II, Phenom II is the better choice for gaming.

So I better wait for i5 processors and their matching socket?
I got an asus p5q with e8400 atm

if that's what you already have, there's really no point in upgrading at this time.

There is a performance boost with i7, but it is not enough to justify rebuilding your system (mb, proc & DDR3 RAM) just to move up to it when you have a socket 775 system already. I would advise keeping your money and saving up for the next "big improvement" in processor technology.

You have an E8400? You are fine, you don't need an upgrade unless you are willing to just blow money each time new tech comes out. If that is the case, upgrade to Core i7. Otherwise, no logical reason to do so.

Wait for westmere CPU (32nm) if ur having performance issues upgrade to a GTX 295 or something. In past experiences I've found that the CPU has very little to do with gaming unless your doing insane overclocks 4.0ghz+.

Unless you have to run a graphical work station for a living, I can't see any reason to upgrade what you have now at this point... :d

Just gaming @ 1680x1050

if gaming is your thing and you feel the need for a performance increase, invest in a newer video card... if you need one

Indeed. I'd stick with the E8400. I got a Q9650 instead in September, and I'm annoyed by how little use the CPU actually ever sees.