talk about speed, and whether or not one processor is 2 nanoseconds quicker at opening a Word document is of scant interest to 99% of the world's computer users. You certainly wouldn't notice the difference, although gaming is one area where raw processing power comes in handy.
Microsoft has effectively put the brakes on the 64bit revolution by announcing that it's delaying the arrival of the 64bit PC and server versions of Windows. The company wants to allow the Windows XP SP2 to have a run for its money, and although you can still get test versions of Windows XP and Windows server 2003 there's not a lot going to happen in tyhat direction for quite a while.
By all means get a 64bit motherboard and processor but for the time being you'll have to be content with running 32bit software on them.
If I was in your shoes I would stick with what I had got for a while - the talk about 64bit computing will go on, but in view of the delay Microsoft will find scant interest from peripheral manufacturers if it asks them to develop 64bit drivers for their products.