Is it worth building a new setup?

My Current Setup is:

E8400 Core2Duo @ 3.00Ghz

G.Skillz 4GB 800Mhz RAM

Antec 300 Case

MSI P43-Neo3 Motherboard

500W PSU with 36A @ +12V

ATI 5770HD

X_x?

I was thinking of getting:

i5 2500

ATI 6950HD

550W PSU @ 50A on 2 +12V

Reference:http://secure.newegg.com/WishList/PublicWishDetail.aspx?WishListNumber=23367868

But my question is.. would it be worth it of an upgrade? X_x or should I just wait it out for more newer things to come out ?

I would ask you how happy you are with the preformance of your current rig. Does it run poorly enough to justify more than $700 USD in upgrades?