Wow, it didn't help for me. In fact on a computer that doesn't even have a GFX card good enough to run Aero(so it wasn't on) it still took up 550 MB running just the OS. I heard it got a lot more streamlined with the new update but I haven't checked it out.
Perhaps. I've not tried Vista since when it first came out, with any luck Windows updates will have fixed all the little things that annoyed me (and not created more...)