Aqua-Soft ForumsIm thinking of getting an 5th gen ipod, but it has been out for what 8 months now? How often do they come up with new ones, is the 6th gen due any time soon? Id rather wait out if its right around the corner.
How often does Apple release new ipods?
http://en.wikipedia.org/wiki/IPod#iPod_models
Check the dates here. Simple enough.
They seem to like Summer and early fall for releases.
If you're worried Apple is going to release another one soon, you're always going to be 'waiting out' as you put it. My opinion is to buy it when you want it so that you can start enjoying it. There's always time to buy a future model down the line...
apple are great for making you feel buyers remorse. As soon as you get to know your ipod 6gen inside out, the 6.1gen will be out 
That's how life is in the electronic / consumer world. It doesn't matter if it's an iPod or a fridge, there's always going to be a newer, better, shinier model coming out 6 months down the line.
They just released an 80gb model; and update 1.2 adds some nice things (like a brightness adjustment in the settings menu).
I'd say, go for it. I don't think they'll release one soon.