Choice 1: If you have limited US income file nonresident return. You can claim moving expenses for yourself and your wife.
Choice 2: You can file resident return as MFJ. You must wait to file the return till you complete SPT test in 2008. Attach W7 of your wife with your tax return.
On joint return, you will report your worldwide income for 2007. You will get credit for taxes paid in the foreign country or may be able to exclude the income.
On your U.S. resident return, you must report your worldwide income. It the total income meets the filing requirement, you must file your tax return.Filing in the U.S. does not necessarily mean that you will be paying taxes in US also. You will get credit for taxes paid in the foreign country. Read:
Your U.S. Tax Return: U.S. Citizen or Resident with Foreign Income