They seem to be doing much better than mine! Mine are about a year old, and they seem to run about half of their original life, and I've used them perhaps 2 hours per day. I was a bit surprised at how soon it became apparent they didn't have their original battery life. I could probably listen for about 1.5 hrs now, but they still charge pretty quickly, so I usually just put them back in the case for a few minutes.
I've had mine almost two years. I listen at work M-F, 8am-11:30am, then let them recharge at lunch, then use them 1:00pm-4:00pm. So far, so issues.
How long do you think I have before the batteries start to degrade?