* to determine if it's "time" to get a 64 bit machine do google around to see what problems and issues people are having.
* you will need different drivers, so as Colin and I have stated make sure the one's you need are available.
* if it ain't broke don't fix it - if you want to move to a 64 bit system only for "keeping up-to-date for the future" (as stated in the original post), and you are able to do your work now without a problem, then you can afford to wait, particularly if you're very busy. Not saying you shouldn't continue to think about and research.
* you don't need to understand assembly language and nor binary arithmetic to understand all this.