Basically:

I did a tweetstorm, by hand, this afternoon about this. Sorry I don't have time to make it a full blog post. I'm just going to copy/paste the contents of the tweets.

1. This Dropbox+Office thing is the kind of thing Microsoft used to do very well. So what if we don't own the platform. We can get users.

2. A lot of other companies wouldn't do it, and the Microsoft of the last decade was one of them.

3. Google could have cut them off with their Docs product. They left an opening for Microsoft, and good for them for seeing it and jumping in.

4. And for Dropbox, in an instant they have matched and passed Google, and neutralized their threat. Google left the door open for them too.

5. My guess, this is Billg's idea. Straight out of his playbook.

6. Other products like this Microsoft did: The CP/M card. All their Mac products. And their mouse worked with all WP's not just Word.

7. So the next thing for Microsoft to do: Take Flickr's business. 1. Clone the API, including feeds. 2. Court developers.

8. You want to win the hearts of developers? Pour resources into moribund markets and get them going again.

9. Speaking of moribund markets. Ahem. http://twitter.com/