cascade replication and multiple primary_conninfo

Hi,

just wondering if PG 9.2 can accept
multiple primary_conninfo on slaves standby servers.

if I understood we can now replicate from slave to slave, tha'ts great,
but with only one primary_conninfo so one upstream server,
is it not a point of failure in case of the slave upstream down ?

sorry for my ignorance, but is a db like pg can work like bittorrent,
take bits wherever it's possible so set multiple primary_conninfo, "secondary_conninfo" etc... ?

Thanks

Franck Madovsky