I'm surprised the price would tank that much.

I think this is a very good thing for Tumblr, Automattic and WordPress. This is awesome to see :)

One thing where I see WordPress.com failing, is in the area of providing an idiot proof easy to use interface for churning out content easily. Tumblr seems to be much better that, so hopefully it can continue and keep it's current simplicity (mostly based on what I've heard from others - I have very little experience using Tumblr).