I'm pretty sure they still do (last time I used one was on a white plastic MacBook). I think it's that white piece of plastic in the bottom of his picture of the opened drive http://4.bp.blogspot.com/-ZXGivS3ZQHk/TsPQFirsZBI/AAAAAAAAA-...

Apparently yes. The manual says ejecting is only possible when connected to a Macbook Air.

yeah the slot loading iMacs from 1999 ish had it on the right hand side. You could press it in with a paperclip. Not sure about now...

The first aluminum iMac didn't, had to send it to the store[1] for almost one month to get my CD back. Will never buy an iMac again.

[1] Country without official Apple stores, that's what you get.

I have to wonder if there was actually a problem with your disc or drive. Everyone assumes an eject button is the magic elixir, but in 5-10 years of supporting Macs I've yet to have a working drive not spit out a disc using one of the regular methods like holding down the mouse button while booting.

I believe they replaced the drive. My problem is that I wouldn't need the drive if I didn't have one by the time but with the CD inside it would make a lot of noise trying to do something to it...