depends on what all is addressed as far as memory goes, some people get more, some less (usually the biggest impact on the amount available is the video card & the amount it uses)
i have to differ i would get 4 GB of ram,money wise makes sense
as far as gaming i cant see how any one with a straight face can
say they don't see an improvement with more ram going from 2 to 3
just my opinion
Actually, kind of had the same question - as I'm building a system around the E8400.....P5Q-E, probably an HD4850 card...to have future crossfire option....I have already a copy of XP Pro....don't want to go now in the Vista...for some time at least...the PC will be used for either gaming/HD Video/Photoshop (me) or Autocad + other usual stuff (my wife).
For this kind of apps - 2 gigs DDR2 8500 1066 is enough? There are some good (after MIR) prices on OCZ...both for 2 gigs and 4 gigs....but I know the problem with XP (32 bit) recognizing less...so it's waste of money getting 4....or get 4....work with 3-3.5 and once I upgrade to Vista 64bit...see all the 4 and perhaps get even more at that time?