i hate to ask this question but why are you getting an iPod touch,, you already have an iPhone...
but to answer your question, i guess syncing stuff will be a breeze with iOS5, AirPlay, iCloud, and all that stuff.
the iPod touch has video cams, so you can now do face chats and all
I don't know man, why would you have another iPod Touch if you already have iPhone? It's nothing but a burden.
If you want something to listen to a pure music player while working out or take a walk, go with iPod Nano. It's a great device for that, seriously.
If you want something iOS but not a phone, well you can go with iPad.
There is no reason for a person having iPhone + iPod Touch at the same time, that's just silly.
I had an iPod Touch, and I sold it just before purchasing my iPhone, I used the money from it to get the 64GB iPhone while I had 32GB iPod Touch. Kaboom! Doubled memory, it's still an iPod and it makes phone calls too.