Google's support of Flash, while never a secret, is now very much a matter of public record. The latest stable version of Chrome - 5.0.375.86, if you're keeping track - includes Flash and even has it programmed to start "on."
A very short and straightforward announcement on the Google Chrome Releases blog broke the news: "The integrated flash player has been enabled by default . . ." Then Anthony LaForge, Google Chrome Program Manager and the post's author, just moved on to mention five security issues that've been addressed.
That's a far cry from rubbing the decision in Apple's face. Still, since Steve Jobs took the time to write a 1,675-word letter denouncing Flash, the move may well widen the split between Google and Apple (especially if Jobs is cranky following all the iPhone 4 complaints).
Anyway, with respect to how the development will affect the average user, the short answer is that it won't. Google's arranged to have Chrome handle all Flash updates, so no one should be forced to deal with an endless stream of notifications. Or even a single popup, which is nice.
This automated approach is smart from a security-oriented perspective, too, since patches will be applied as soon as they're available.
Finally, Google is prepared in the event that any problems crop up. Issues can be reported here: http://code.google.com/p/chromium/issues/entry