Will you have a way to keep your current iTunes account active? If you keep a US credit card and mailing address, you should have no problem. Also you can always add money buy having someone send you iTunes gift cards from the US.
I'm an expat living in Australia and my US credit card statement gets sent to my employer's address and they forward mail to me. I have kept my US account and can still download apps and music/video from iTunes. This is great because I can keep up to date on current US TV shows, etc.
I also opened an Australian store account using my local credit card. You need to use a different e-mail address, but you can have additional accounts authorised on your iTunes. I've used it to download a couple of Aussie only apps and songs that weren't available in the US store.
All apps sync fine to my iPod touch. I normally stay logged into my US account. I just have to remember to every so often log into the Aussie account to check for app updates. You'll only get automatic notification of updates for the account you're actually logged in to.
Hope this helps!! Good luck with the move.