Though we tried to preserve external API, two branches, 0.2.x and 0.3.x, differ drastically:
As before, the root module pyroute2 re-exports all important classes, so if you used from pyroute2 import IPRoute, nothing changes then.
The most important part of the release 0.3.2 is that all the cluster-specific code, all the internal messaging etc. was completely deprecated. Since 0.3.2, pyroute2 uses only simple threadless socket-like objects to access different Netlink protocols. The only component, that still uses implicit threads, is the IPDB module.
So if you still to use distributed infrastructure, use specialized libraries like ZMQ or AMQ. Probably, pyroute2 will have later its own messaging proto, but not integrated in the core, just as a separate module.