If you got money to burn then go for it.
Otherwise, why do you need 64-bit computing? Unless you do corporate sized database crunching or heavy duty video editing (like on a Hollywood level) then it's really just a waste of money right now. The market is very new and prices will eventually drop.
Driver and software support is not up to snuff yet on a wide scale. So, any problems you have will be very dicey in resolving. Last I checked Logitech drivers and Dell monitors were a no-show for compatibility.
I'm just your average joe, so I'm waiting it out at least for a year to let the industry catch up to 64-bit and to let everyone else work out all the bugs for me.
But it's only one man's opinion.
p.s. for what it's worth, Win98SE will always have a warm place in my heart as the uber gaming platform. Used it for years.