Upgrade non-exit relay from old Vidalia to Vidalia 0.2.15 and get marked an exit relay
Start with Vidalia 0.2.14. Click "I want to be a relay" from the 3 choices, then go to the exit policies tab and unclick all the boxes. Save, run it as a non-exit relay for a while, etc.
Upgrade to the Vidalia bundle with 0.2.15 in it. It will happily realize that your previous "I want to be a relay" choice means that you wanted to be an exit relay, so it will choose "I want to be an exit relay" from the 4 choices.
This startled at least one user as they upgraded, who then reported it to me. The user was on OS X 10.6.8 using the Vidala bundle fwiw.
I think the actual choices in the exit policy tab remain the same, so this is just a scary interface problem and not actually a dangerous bug.