I deleted my POP email in Thunderbird and went through the configuration steps in gmail help. The final step was to enable IMAP in settings.
To my horror, its not there! It still says "Forwarding and POP", when it should have said "Forwarding and IMAP/POP".
I read the official announcement again, and found this tiny disclaimer
As we roll out the feature over the next couple of days, you will be able to use Gmail at work, in your car, or just about anywhere on any device, and actions you take will be automatically synced with Gmail on the web (and remember it works the other way too: anything you do on the Web will be seen on your phone or in your mail client). Just click the "Forwarding and POP/IMAP" tab in your Gmail "Settings" and turn it on. (Psst. If you don't see the "IMAP" in the "Forwarding and POP/IMAP" tab, then check back soon. We are giving it to users as fast as we can).Gosh Darn... Now to wait and watch.
Myopic view of gmail