Ok,
checked 1 benchmark and it came out that your phenom 9600 is actually a bit slow.
My Intel Core 2 Quad Q6600 2.4Ghz which i got in 2007 was better in many test.
Here is the link to that benchmark between my q6600 and ur phenom.
http://www.extremetech.com/article2/0,2845,2226942,00.asp
Anyway I still think that you could hold on to your processor for a while.
Depending on how many free Ram slots you have I would get it up to:
*in case of 2 more slots to 8GB
*in case of 1 to 6GB
I have 4x1GB Ram 667Mhz and as soon as I am able to change that will get it up to 4x2GB which should do for another while.
My computer is getting close to the edge where new games won't be looking so good on it and then will have to change some stuff in it.
My Nvidia 8800GTX is sweating to deliver everything on high in Test Drive Unlimited 2 with 1680x1050 resolution.