Upgrading for Darkfall 2.0! Help

With DF 2.0 near I was looking to upgrade what ive got so this time around i may be able to function during sieges a little better. Was wondering what the best bang for my $ would be on about a 300$ budget to upgrade this computer. I can spend another 200 or so in about 6months if need be. I am mainly considering mobo an CPU due to the fact I had heard several times DF is more CPU demanding them most games rather then GPU but that may just be garbage information. Here is my current set up.

AMD Phenom II x4 955
ATI HD Radeon 5850 1gb gddr5 Core Clock in MHz 850 MHz Memory Clock in MHz 1200 MHz
MoBo Gigabyte GA-MA790GPT-UD3H http://www.gigabyte.com/products/product-page.aspx?pid=...
8 gigs of ram
64-bit operating syst

I was wondering if there are even any upgrades worth spending on at this time in that budget range. I havent touched this computer in about 2 years now.

Thanks in advance for any advice. Also I am not opposed to trying Intel if needed.