Upgrading Graphics card and ram

I have a pc with the following specs:
GA-P35C-DS3R
8800GTS 640mb
E6750
4gb Elixir (no-name, value, ****) DDR2-800


Ill be wanting to upgrade soon but i am just wondering if it is worth it when Intels Nehalem is coming out soon.
I want to get a HD4870 1GB, and 4GB of new ram so i can OC my CPU, my current ram doesnt go a single hz over their rated speed and i dont even dare to overvolt them.

Obviously a HD4870 would be usable on the Nehalem but the ram is where my question lies.
My current mobo have 2 DDR-3 ram slots, so is it worth spending money now on some DDR3 sticks? or should i just get some really good DDR2 ones?
I know Nehalem uses triple channel so that might be the problem that in order to run triple channel i would need to get a single new stick of DDR3.
So, should i stick to DDR2 and get some good ones since they are pretty cheap, or should i go for DDR3 now?
Also i am right when i say the HD4870 is better than the GTX260 right?
And finally, is it worth getting an E8500/8400 instead of my current E6750? I'm not going to overclock very much, just like 3.6ghz if my mobo can do it. Of course i will get a sufficient cooler and paste (Xigmatek and AS5)

Thank you for all the replies

Your RAM should still run at an FSB of 400, so I see no issues in keeping that, getting an E8400, overclocking it to 3.6Ghz, and waiting a year.

Yes 4870 is the better deal still.

RAM. It's 800Mhz RAM and will run at 400 FSB. To overclock an E8400 to 3.6Ghz, you increase the FSB from 333 to 400.

CPU: 400 x9 = 3600

RAM: 400 X2 = 800

You don't need new RAM to overclock your CPU.

Thanks for the replies, the OCZ is 1066 so i just need that, a cooler and the HD4870 and im set for another year or so
Thanks again