A little friendly upgrade advice from you pro's please

[Born_2_Kill_83]

My current specs:
Asus P5B-Deluxe
Asus 8800GTX
4GB OCZ Gold PC6400
OCZ Gamexstream 600W PSU

I'm going to wait for the GT200 GPU's and stick with my GTX for now, but I want to future proof my MB and RAM.

I want to spend around £150 on a new MB no more than £200, and I would prefer to stick with Asus if possible.

Should I get an X48 MB or settle for an X38? Also will a DDR3 MB run DDR2 ram?

Which brings me onto my next question, should I upgrade my trusty OCZ 800MHZ to some PC8500 stuff, (Not keen on the DDR3 prices at this present time) or wouldnt I see any performance increase?

A few troublesum questions I know, your help is greatly received

 

[Born_2_Kill_83]

I don't think that the X48s offer anything all that compelling over the X38s in general but other views may vary.

DDR3 and DDR2 are not interchangeable, some motherboards do offer slots for both but you can't use both types at the same time and the ones that do allow the different types tend to be aimed at the budget end of the market - mildly odd given the somewhat extortionate price of DDR3 currently.

You are only likely to see a performance increase by changing the Ram if you are overclocking pretty heavily - you don't mention what CPU you have but unless it is one with a 1333mhz FSB I suspect you aren't currently stretching beyond what PC6400 is capable of yet.

Soz using a Q6600