I am soon to be getting a new machine and i am now contemplating the idea of moving onto 64 Bit Vista. Only problem is development wise, most of my stuff is in .NET now days and i hope to kill off what ever ties i have with VB6 etc...

So from a development point of view is it a good idea? And if so how hard is it to provide applications that target 32 Bit systems that are developed on a 64 bit system?