This is great! Google acknowledges that the visual programming environment is closely related to Scratch, a visual programming environment that works brilliantly on desktop computers.
I've always thought that Scratch would be a great way to program phones, so if Google does a nice job of this I'll consider Android when I need to replace my phone.
Scratch itself is written in Smalltalk, otherwise I'm sure we'd have seen it ported to mobile devices before now.
It will be interesting to see how much App Inventor allows you to do.
The docs are already up:
App inventor allows you to play music, display images, perform computations, animate sprites, detect collisions, play videos, access the phone's contacts list, create and manipulate lists, store data to a simple database, dial the phone, send an SMS, interact with twitter, read the accelerometer, read the GPS, determine the phone's orientation, scan barcodes, open the camera app, load a web page, perform a web search, open Google Maps, display alerts, append to a log file, convert text to speech, use the phone's speech-to-text detection. In the "coming soon" list are things like a game client, web database and voting system.
So I think the limiting factor will be human creativity rather than what App Inventor allows you to do.
you have to submit a form to get approval to use it :'(
Google releases many of their new products by application only, i.e. you have to submit a form. When the product is more robust and polished, they open it up for wider use.
I submitted a form a couple of days ago, but haven't heard back. The questions on the form suggest that Google wants to see this used widely to teach software development in the classroom.
I can't think of a better software platform to teach programming to high school students.