One of the things I always encourage people to do as part of an acquisition is to handle the transition gracefully (1 year-ish), and then start looking around for what else you might want to do inside the acquirer. Often there won't be anything, and you can just bide your time or flee the scene - but other times there might be a perfectly interesting job elsewhere in the organization that you can use to build your skills, beef up your resume, and live out your golden handcuffs.

But too many people that I see just sit there, quietly miserable, while their product dies around them.