I just quoted an email in a reply, and when I mouse over the quoted text, a round-cornered frame appears around it, with a Dashboard-style (X) close button at top left. Clicking it deleted the quoted text.

I have never seen this before. I then tried quote-replying to other emails and did not get that feature. Tried replying to the same email again (nothing fancy, no attachments) and there it was. Now today it doesn't happen!

Has anyone seen this? Did some bug accidentally enable a feature that was disabled by Apple?

It's nothing terribly useful, but it's very polished and certainly seemed intentional.

STROGG: Change We Can Believe In