The technical answer to your question is that dues are assessed by calendar year, so the 2009 dues have already been billed and should have been paid. If they have not been paid, they'll have to be paid by somebody before the deal closes, I believe.
On the 2010 dues, you will receive a bill for the 2010 dues in December 2009 and you will have to pay them.
In a resale, everything is negotiable. The normal deal is that you do not pay dues for banked points you might get (they're a deal-sweetner and may already be reflected in the price), nor do you pay for points you will not receive. The price of a stripped contract may already have been set lower to adjust for the dues you'll have to pay. But I'd be sure you have a good idea what those dues are and that appropriate adjustments are made.