What do I have to take into account if I want to replace my iPod touch with an iPhone? I have an iPod touch which is regularly synced with my PC/iTunes at home. I have bought some apps and music.

Can I easily plug in my new iPhone (I don't have it yet), start iTunes and have it synced with it? Will all songs and apps be copied on it? And will the apps be running on the iPhone (speaking of license).

What about my mobileMe-account? Will it be synced correctly after I setup the account on the iPhone?

Do I have to check out or unsubscribe the iPod? Or can I just reset it? Again, speaking of license here.

I hope I could make clear what I mean.
I've not tried this myself but this guide on ehow.com makes it look fairly simple using iTunes.

Basically as long as the host computer is authorised for iTunes use, you can connect your old iPod, right click on the icon from within iTunes and select Transfer Purchases to get the apps onto iTunes. Then connect the target device and sync the applications to it.