Do they have all of Tumblr’s raw materials, and just haven’t combined them into a form that maximizes their collective value?

Not that I love Blogger’s interface, by any means.  No doubt in my mind that Tumblr’s superior there.

But I love the fact that Google Reader lets me assimilate sites regardless of publishing platform, something currently missing from the Dashboard that – while certainly possessing the potential to complicate – could take Tumblr to a new level of utility (and dramatically increase the time I spend there).

I’m just curious what part of Tumblr’s success can be attributed to the publishing portion vs. the dashboard/reader part.  And I’m always fascinated by how much Google blew it with Blogger.