I took a screengrab when it happened this morning. It looks so nicely formatted it's so very tempting to click it :-)
It's possible it may be legit, but whether or not Adobe recommends only updating from their site, when you embed Flash Video etc in a page using Dreamweaver it has version checking code which will ask you to update if you have a lower version of Flash.
So if someone visits one of our client's sites where we've used Flash Video, they may be asked to upgrade.
How is Joe Average meant to know the difference?
I only didn't install it because a) I don't trust social networking sites and b) I know for sure my Flash is up to date.