I will be moving from Massachusetts for New York for school, and I know that New York requires you to register your car within 30 days of becoming a resident of New York. The tricky part is how they define resident:
"Section 250 (5) of the Vehicle and Traffic Law defines the term "resident." The law defines a resident as a person who lives in NYS with the intent to make NYS a "fixed and permanent" place to live. To live in a house, a home, an apartment, a room or other similar place in NYS for 90 days is considered "presumptive evidence" that you are a resident of NYS. A police officer can use this evidence as the reason to issue a traffic ticket if you drive in NYS without a driver license or vehicle registration issued by NYS.
A judge considers the law and the evidence of your intent and decides if you are a resident of NYS. For example, if you pay taxes or your children attend school in another state, a judge considers these facts to decide if your intent is to make NYS a "fixed and permanent" residence. The DMV will not decide if you are a resident of NYS, if you must get a NYS driver license, or if you must register your vehicle in NYS.
According to this law, students from other states or from other nations who attend school in NYS are normally not considered residents of NYS."
I'm guessing that other states are similar. Personally I am happy about the move because it means I'll be paying less for car insurance.