and haven't you, kind of, just done that? ;-)
Well... There's _always_ going to be new hardware. I made my mind up and ordered my new PowerBook. KNOWING that I could have gone for the 1.5 GHz version in about a month, I still chose the 1.33 GHz version of the 15" PowerBook. My typing's too good, so I don't even need the backlit keyboard. SuperDrive? Ah, hogwash - I just need more screen real estate and a bit of speed over my iBook/800.
My iPod is a 10G second generation one, and all of my music fits on it right now. It's the perfect companion on travels, it's my big stereo's jukebox. It's just fine. Been the best hardware-buy I've ever made. Didn't lust for the 3rd generation, although the miniPod made me count my money (and it's still not available here...).
The PowerBook will certainly do me well for a year - and it'll continue the year after that - unless I _have_ the money and Apple _has_ a good PowerBook G5 by then, that is.
And yes, don't forget that you can still sell your iPod if a new one comes out. Just make sure you sell it before prices drop too much. And keep it in good condition 'til then.