What do you make of Yahoo's purchase of Tumblr?

As I'm sure you already know, given the amount of coverage in the media about this story, Yahoo has purchased the extremely popular microblogging platform, Tumblr for $1.1 Billion dollars.

Given Yahoo's rather checkered past, what do you make of this purchase? How do you think it's going to affect Tumblr as a platform? What do you think it will do to Tumblr's “cool factor”?

Yahoo hasn't had the best luck with acquisitions. It picked up Delicious and basically destroyed the popular bookmarking platform. Sure, it still exists and is used but it's a shell of its former self. The same applies to the former web darling, Flickr.

Adding fuel to the fire, WordPress founder, Matt Mullenweg has pointed out on his personal blog that they've seen a huge number of people jumping ship from Tumblr to WordPress.com

Imports have actually spiked on the rumors even though it’s Sunday: normally we import 400-600 posts an hour from Tumblr, last hour it was over 72,000

Now, having said that, this is really a drop in the bucket to Tumblr who boasts a huge 109.5 million blogs on the platform but if the migration keeps up (and I'm sure we'll find out soon enough if it does) then this could be a sign of bad things coming.

Personally, I'd like to see Yahoo! pull this one off correctly. As long as they keep their horrible Yahoo! sign in away from Tumblr and don't try messing with the serving of ads on the platform, Tumblr could very well benefit from this arrangement.

I think, however, that the reason people are jumping ship is because normally when acquisitions like this occur, it's only a matter of time before the services fades away (take Posterous for example)

That's my opinion on the matter. What's yours?