E8400/4870/4gb RAM. Upgrade or New system?

Currently running the config you see above. E8400, 4Gb DDR2 Ram and a Sapphire 4870 all running stock clocks. Thinking about doing an upgrade or building a new rig altogether. Power isn't an issue as I have a Quattro 800 in my rig. A few things i wanted some input from the community on.

What it's used for: Gaming, mostly. Both graphic (some games from the last few years and upcoming games) and processor intensive (physics based games like Cortex Command), other basic stuff like internet browsing, non-hi-res video, music.

Firstly, Upgrading to a better GFX card. This is something i could do now, and still have if i choose to buy a new board/chip/RAM at a later date. If I were to invest in a higher level Graphics card (I've always preferred ATI and Sapphire) would there be a bottleneck on my system? Could I push my system further by adding a graphics card or will it be limited by the processor and chipset?

Secondly, I've heard of a new chipset that Intel has in the pipes that's boasting a 20 percent performance increase over SB that's due out within a year. Is it feasible to wait for this or should i just spring now?

Lastly, If i do go ahead and get all new parts i'd like to build the old one into a linux PC, possibly to run as a server for whatever game i'm playing with.

Ideas? Input? Appreciate it!

you could upgrade your graphics card to a 6950 for $250
http://www.newegg.com/Product/Prod [...] -_-Product
and since you mention you know about the new intel chipset (X79), you could save some money until then and use the 6950 in your new build

idk if it would be bottlenecked, maybe someone else can explain but even if it is i would think that it be an upgrade over your 4870

in the meantime you could just upgrade your graphics card and monitor if you want to something like this which is on sale for $189.99 at newegg (w/ promo: EMCKDKA47)
http://www.newegg.com/Product/Prod [...] 05235-L08B

and save the rest you would have spent on a SB rig until X79 comes out

http://www.newegg.com/Product/Comb [...] mbo.634210

Price on the 1gb version and a p-IPS monitor. A little more than i'd like to spend but I like asus so. . .

I do have an aftermarket air heatsink on it, not unlike http://www.newegg.com/Product/Prod [...] 6835233081

(note: it isn't that, but it's very much like it, copper heat pipes surrounded by aluminium with a fan in the middle)

I'm sure it should be able to OC and fairly easily from what i've read. (e8400 has a rep for good OC's even on air) I'm running it on an asus p5k-e/wifi-ap board, and apparently either the settings aren't that good or i'm not that good because i tried OCing it and any little bit would cause it to just cycle at boot. I'm not that experienced at OC'ing but I consider myself to be good with computers and i was reading a walkthrough so i'm not sure if the board doesn't like it or i'm just crap at it or what.

Either way I'll probably take a second look at it and see what's what.