Just updated myself, fliptwister, and although Gmail notifications didn't seem to work at first, they do now - maybe after changing to detailed notifications? Are they working for you now?
Have you turned on 'Show with details' under 'Advanced Notification Settings'?
Still no notification for me. Turned on "show with details" on watch notifications setting. Is that what you meant?
Yup. Although that was a shot in the dark - I'm not actually sure what got them working for me (when I first updated, they still didn't work, but after some fiddling around and a restart, they work now). I also have 'Show alerts even when phone is in use' on BTW, and I don't think you will get an alert if the watch isn't on your wrist, of course. *Edit*: Also, when testing it, send the e-mail from your phone to yourself - oddly, when I send it from the desktop, sometimes it doesn't show up at all (or takes forever).