Timeframe: Within 3 months.
Watch the video here: Adobe announces Flash Player and AIR for Android
So within 3 months, every web developer should work hard to make Flash irrelevant for Android. Is it time to say that computers are fast enough (including phones) to do everything that Flash can do with JavaScript, <canvas>, SVG, and HTML5? If not, then we are so close Flash STILL does not matter. This is why Youtube has started their HTML5 beta, a lot of other video sites have an HTML5 section. It is working great and it is definitely faster than a Flash 'applet' loading then the video loading.
The only issue is that Youtube (and most other sites) have decided to use h.264 instead of non-patented formats like OGM. And while OGM is good, it was never designed for HD. This is something set to kill Firefox's market share in favour of Chrome, since Chrome DOES support h.264 in <video>. Since Chrome is essentially the browser on Android, then that phone is all set.
In terms of games, I've seen plenty of nice games in <canvas> that are equally as responsive (and in terms of code a similar development time) as any game in Flash. And the same is possible with JavaScript and SVG. Since ActionScript 3.0 is based on ECMAScript it is clear Adobe acknowledges the risk of losing market share to standardised and their dream of binary Internet is almost over (where one cannot see the source code).
That sentiment is all well and good. But it's great that we are getting Flash since there are so many uses in place for it already.
Android uses a version of Web-Kit for its browser, but Android does not use the Chrome browser... yet.
Imagine all the free flash games you can play on the go.
Not happy enough to invade our PC's with crappy and insecure software, they will try to conquer a Linux based mobile platform.