That's what StatusNet is; it supports the OStatus protocol: http://ostatus.org/
Google is also creating a (incompatible) federated microblogging system using Atom+WebFinger+Salmon. http://www.google.com/buzz/dclinton/HeMv1AQTXS8/Envisioning-...
Google is also creating a (incompatible) federated microblogging system using Atom+WebFinger+Salmon. http://www.google.com/buzz/dclinton/HeMv1AQTXS8/Envisioning-...
I find this new Web 2.0 flavor of spec mashup as hard to follow as a Twitter conversation. I wish people would provide a complete spec (if only as an "informative" adjunct to the real spec) rather than including-by-reference ten different sub-specs, none of which make sense in isolation.
I tried looking into OMB for a side project about a year ago and had a very hard time finding any clear documentation, and just looking again now it doesn't seem any easier.
OMB -> OStatus
Identica -> Identica