I am relocating from NY to PA. I will lease a residence in PA and work there 5 days/week, and still own home in NY. Will I owe any NYS income tax on income earned in PA? In addition I am being paid supplemental income for next 6 months. If I change my residency, can I also change this income over from NY to PA?

Any income earned while in PA must be reported to PA.

If you are keeping your home in NY, NY will consider you resident of NY.
You will report your worldwide income, including income earned in PA on the NY tax return. Also claim credit for taxes paid to PA. Your U.S. Tax Return: Working or Living in Two or More states (http://taxipay.blogspot.com/2008/06/working-in-two-or-more-states.html)

Once you lease the apartment in PA and start living there 5 days/wk, as long as your intent is to be a PA resident then you are a PA resident. Your NY home becomes a second hoime (vacation home), and you no longer owe NY tax on your income. This first year you will have to file a part-year resident retun with NY and a part-year return with PA. Then in 2011 you are a full-year PA resident and no need to pay NY anything (assuming you have no NY-source income).

Some advice: start using your PA address for all correspondence - especailly tax filings - so that you have evidence for NY that you are no longer a NY resident, because as Mukata says if you keep the home in NY they will try and collect income tax from you. Trade in your NY drivers license for a PA licnse. Also keep a diary that shows nights you spend in NY versus PA, again to document that you are spending more nights in PA.