Updates if iPhone and relation to iPod touch

I'm looking to wait for the free iPod touch with the purchase of a mac. I'm hoping the mac will update just before this, but that's not a big issue. I've seen in the past that it looks like the iPhone and iPod update about the same time.
Is this true?
Weren't these updates just about the same time as the free iPod offer for students?

Idealy I'd like to get an updated macbook w/free updated iPod. Is that how it worked last year?

I've looked into buying a used iPod and can't understand how they can ask that much money for them. One was broken and $20 less than a new one. Not worth the trouble esp when they'll be free soon.