Based on my experience you will receive '08 points, if you purchase before July 31, 09
I purchased an add-on Dec UY in Nov of 08 and I received 07 and 08 points. They also allowed me to bank the 07 points even though it was well pass the banking deadline. Also I paid only 1 month of MF's for the 07 points. I don't know if this is always the case, but that's what happened in my situation.