It should finish up pretty darn quickly.
A couple of years ago, we did a mild swap. The goal was to brew the beer, keg it, carb it up, and ship it out in exactly 10 days. We all did that, and it was great! I have to admit that my mild was better after about 3 weeks, though.
If you pitch the correct amount of yeast (consult mrmalty's pitching calculator) and keep it at the optimum fermentation temperature, two weeks is more than sufficient as long as the FG readings are stable.