I definitely think that this is a sweet deal. If you want to come here, you should be in it for the long haul. Traditionally, the FAIPs have done very well here because they have plenty of time to learn the jet and still keep up with the expected career enhancing assignments.
With that being said, I've known guys to leave the U-2 for AETC tours, AFSOC tours or back to their original MWS. I've also known a C-21 guy that flew U-2s for a few years go to F-16s. He spent a while flying F-16s AD then spent a few years flying F-16s for the reserves then came back on AD to fly U-2s again (where I met him). He flew with us a while, but then landed a job flying F-16 aggressors down at Weapons School.
My point here is that you need to join the U-2 program because you want to be a U-2 pilot. Period. Huggy and I are part of the hiring process (as are all of the U-2 pilots) and if we smell that you are using the U-2 as a stepping stone to another aircraft or program, you won't make it past the interview. But, once you are here, if you find it does not meet your expectations, or you are unwilling to do the job, there have been plenty of pilots who have found other flying jobs. This is not a "dead end" job.
There have been a few long term DNIF pilots in the program recently. I don't know why, how, or when their problems manifested themselves, but they are well taken care of. We have found flying jobs or career enhancing staff jobs for all of them.
We are a brother/sisterhood; we take care of our own. In answer to Razorback's question we are 11R and we have the same flesh peddler as the other platforms, but we have never been limited to sending a guy to RJ, RC, AWACs, or the global hawk.
If you are curious, take a look at www.beale.af.mil and the U-2 pilot application on the right hand side. Give a call to our chief of recruiting, Maj Merten, and get the ball rolling.