are we gonna need the DDR400 ram for Future Proc?

[DinoGucci]

i am kinda clueless about this and i cant realy see it. is the DDR400 200FSB gonna come handy for future processors? for example the new P4 533MB ones? i mean i realy have limited info about ram but if some one would explain whats the difference between a DDR333 and a DDR400 on a Future processor overclocking. thanks alot!