Dave,
You've received some wise counsel over the period of this conversation. Good to have others' perspectives. You got to admire the last guy (TX Nov09, NYC Marathon Nov10!).
Diagnosed as a child, I still pushed myself, and was mountain climbing and cross-country biiking at age 30. Then my FEV1 went down in the low 20's for a while ten years ago (when I was 40yrs old). My doc charted my recent lung decrease over time. The graph showed I might survive 18 months. The xplnt list was taking two years (old system). I got on the list, and began to put my effects in order (I had a wife and two kids in middle school at the time).
Then my lung function came back up into the 30's. After a year there, I asked to be excused from the list. My lungs went up into the 40's in the ensuing years. Even hit 50% once a couple years back! WooHoo! I was biking, hiking, and refurbishing houses for fun and profit!
Now I'm 50. My lungs have recently plummetted back down in the low 20's. Went back the xplnt team. While testing me to re-qualify for a transplant, they discovered a heart problem. They say the heart would not survive a tranplant surgery. (But the heart surgery would be too much on these lungs.) So now I'm trying to find creative alternative.
Still working my desk job full time- though about half of it can be done from my home office while doing lung clearance.
I'd join those who encourage you to go for it soon. It can be a bit of a wait even on the new system. If your lung function comes back up, you can pass until you really need them.