Well, you could go into Time Machine and restore stuff manually.
Or, when booting from the install disk, you could restore an entire system.
But since I'm guessing you have a "new" OS for a reason, I'd use Migration Ass
t since it acts like you're moving to a new machine, which in a way you are. So it optimizes for that kind of move. And you could still manually move other stuff if you need to.
Rob