They work so slick and simple and perfect for duplicating on tumblr and wp, even with format types, just like I posted it myself.
It would be waaay cool if WPMU DEV forked these two plugins, combining them to one, but so they add three features:
1. Worked with a subdomain multisite,
2. Option to allow subsite admins, but not requiring, to get oAuth credentials for EVERY subsite on a multisite. If the superadmin wants one set of oAuth keys for the entire multisite, he can.
3. Admins could define:
a. What access level is necessary to "connect" to tumblr/wp.com (ie: Contributor)
b. If the connection is for the whole site (or subsitesite of a multisite) OR per author of the site.
You could add other services, like a Twitter push that sends the original permalink, rather than wp.co links. But the beauty of these plugins is that they are only wordpress and tumblr.
This guy did an awesome job, especially since it deletes posts from tumblr/wp.com if you delete them from your site. Athough, the wp.com plugin needs some work, still in beta. It adds about 7 bullets to my posts at wp. The admin area could use some cleanup, but on the front end it really really looks better than JetPack's Publicize which just serves as a wp.com advert. IMHO, these really need to be one simple plugin within your premium pack. Honestly, I'd hit the guy up to join the dev team because it's such an awesome plugin, but IDK.