The Military Spouse Residency Relief Act (MSRRA) allows the military spouse "to claim residency in the same state as their sponsor and retain that residency as long as the servicemember is in the military."
This means military spouses now have the same privilege as servicemembers to pay income taxes to their home state, and not have to change their driver's license or vehicle and voters registration during each permanent change of station.
This used to be one of the biggest pains for me because it impacted my ability to vote and increased the already-complicated tax filing process. (One year, I had residency in three different states! That made filing taxes so much fun.)
I only mentioned residency, voting and taxes in my example above, but the MSRRA impacts the following:
Residency, Voting, Taxes, Driver's licenses, Automobile registration, Property ownership, Education benefits, Divorce, Wills, Estate plans, Powers of attorney
So, this is no small deal! If you're a military spouse, find out all you can about the MSRRA and take advantage of the relief now.