Replication

Looking for replication solutions, I find:

Slony-I
 Seems good, single master only, master is a single point of failure,
 no good failover system for electing a new master or having a failed
 master rejoin the cluster.  Slave databases are mostly for safety or
 for parallelizing queries for performance.  Suffers from O(N^2)
 communications (N = cluster size).

Slony-II
 Seems brilliant, a solid theoretical foundation, at the forefront of
 computer science.  But can't find project status -- when will it be
 available?  Is it a pipe dream, or a nearly-ready reality?

PGReplication
 Appears to be a page that someone forgot to erase from the old GBorg site.

PGCluster
 Seems pretty good, but web site is not current, there are releases in use
 that are not on the web site, and also seems to always be a couple steps
 behind the current release of Postgres.  Two single-points failure spots,
 load balancer and the data replicator.

Is this a good summary of the status of replication?  Have I missed any important solutions or mischaracterized
anything?

Thanks!
Craig