if it came pre-shipped with 64 bit then normally there is nothing you would have to worry about. all 32-bit programs should work normally. The only problem would have been if you upgraded yourself from 32 bit to 64 bit, you might have had hardware which didn't have drivers that are compatible in a 64 bit environment. But since it came shipped, I presume the manufacturer took care that all your hardware is shiny brand new and has any 64-bit drivers you might need.

edit: and yes, if you get your hands on any 64-bit version of an application, it of course runs a bit faster and smoother under 64 bit than 32 bit