Hardware is more important than OS.
Based on the fact that you mention a laptop with Vista, I'm guessing a single or dual core processor, 2 GB of RAM or less, and probably a 5400 RPM drive. Means your editing efforts are going to run a little slow regardless of what tool you use. My desktop is twice as old as that, but has adequate RAM and fast disk - and it's kinda slow compared to my modern laptop. But, don't make that your limiting factor. You can do certain things like make sure you have 25% free disk space, clear out temp files, run scandisk, run defrag, make sure your OS is updated with patches and service packs etc and that should speed things up a bit. None of that will cost a thing. If you'd like some more detailed pointers in this arena, just ask.
Regarding NX2, can anyone give me any reasons why I might consider adding it to my normal workflow? I do 99.5% of everything in LR3, then move to CS5 on the rare occasion I need it. I know there's lots more to learn on CS5, and I'm gonna get there, but I just don't use it much right now. When I do use it, or learn something new, I am always amazed at the power - but I wouldn't use a sledgehammer to hang an 8x10 on the wall
I hope to take a class or two in photoshop at some point. Just a matter of time and money!
Academic software licensing can be a better deal than the prices mentioned as well - a friend is a student at Indiana University, and he got his CS5 for *free* downloaded off the school's network - IU has such an agreement with Adobe. He could've gone to his bookstore and got the full CS5 suite - the 'Master Collection' - for $50 - this is normally a $2500+ purchase from Adobe!
Keep in mind, the agreement with Adobe is that you will actually pay for the software when you are no longer a student - the academic licensing is for use while you're a student.