Quite a weird press release - but I guess with Yahoo's record of the past it is better to be clear and honest upfront. "We wont srew it up!" - Yahoo will run Tumblr as an independent entitiy very much like Microsoft handled the Skype acquisition and very much unlike Yahoo handled their last significant acquisition - the purchase of Flickr which has been basically left unchanged for years even though it used to be the best photo sharing site on the web at the time of the purchase. It'll be interesting how this integrates with other Yahoo! services over time - if nothing else it adds 300 milion unique users.