Or you could wait, making sure they don't expire by a bit of online shopping or hotel/car credit, to see if the 2012 combined UA/CO program will retain UA's very popular one-way awards.

UA Mileage Plus brags about their varied award choices in a lot of their marketing, and IIRC, the new head of United Continental Holdings' United Loyalty Programs is from Mileage Plus. I'd give about a 70% chance that we'll have 1-way awards on the combined NewUA program.

I'd also give about a 20% chance that prior to that, they'll rollout a CO<->UA mileage transfer program just like NW/DL did around this stage of their merger. Throw the customers a bone to arbitrage slight differences between current programs and use "orphan" miles in one program to top off the other. The upside is, your customers are building your necessary database for the later account combination, without your data analysts and developers having to do all the work.