Win 64 bit, will I be sorry?

Did I bite on the 64bit hype?

I am putting together a new system:
P950D processor, 4 gigs of ram, Abit AW8D MB, Tons of storage.
My main "bread and butter" work is motion graphics in After Effects. I have the latest version of the production studio, and use and like ALL the applications, premiere pro, audition, encore, and so forth.

I bought Win 64 for the OS because, well the processor said 64bit, and I hoped to be able to use all 4 gigs of ram...AND, I also like 3D work, and many of those apps are coming out (like vue 6).

Anyway, I have read some more on the net about win 64 and issues with drivers and apps, the 3 gig switch (what ever that is?) dual boot systems...do I have to spring for ANOTHER copy of windows.

Again, this is a work / graphics / video editing machine. No games, no web stuff...

Any thoughts about my choices?

JP