are you taking the standard deduction or itemizing? the standard deduction is now over $30,000, so you get that deduction whether or not you have the interest (or the state and property taxes) to deduct.
Also, what is the interest rate on the mortgage and where is the cash going to come from to pay off the mortgage? For example, if your mortgage is a 3% and you the cash is sitting in a CD making 4-5%, there is no incentive of paying it off. However, if the mortgage is let's say 6% and there is cash in the bank earning 3%, then there is an arguement to be made to pay off the mortgage.
to me, it's not really about the tax implications, it's really about what the alternative return on the cash is that would be used to pay off the mortgage.
there is also the 'peace of mind' factor that the home is owned free and clear, no matter what financial mindfields occur in the future.
