Brad DeLong is puzzled:

“I am supposed to be smart. I should be able to find a way to use all of these in a way that is truly useful…”

And then goes onto enumerate a very small selected subset of the numerious sites that are building out interesting user facing services: Tumblr, Evernote, Jott, Sandy, del.icio.us, and Skitch.

Me thinks: These tools are what in the software industry we call features.  Each firm is taking a swag at building out a feature in the hope of being acquired when the roll up happens.  The firm’s motivations to enable cross application integration are weaker than the end user’s.  The firms are striving to retain options.  We haven’t reached any sort of consensus about where the locus of the roll up will be.  We haven’t solved the authentication problem that’s a foundation for the whole problem.  Many highly contested issues here.  The shake out won’t be pretty.

It’s only very peripherally about you Brad.