issue with 9.0 1 slave becomes master with new timeline

Hello,

I have an issue with the following architecture:
1. master
3. slaves with streaming replication (used for backup and read-only queries)

When the master goes offline, 1 of the slaves must become master. Thus
I am creating trigger_file and the slave becomes the master.

The problem is that the other 2 slaves are using timeline 1, when the
new master is in a different universe.

How can I easile migrate the 2 slaves on the new master without
creating a new base backup (which unfortunately takes too long as the
databases contain arround 200GB)?

Shoud I use pg_resetxlog? If yes, what is the command?

The problem is that the slaves are used for reading and I really need
to have them synced with the new master in matter of seconds not
minutes (the slaves are distributed globally - 2 in us, 1 in europe, 1
in asia).

Thank you.

PS:
you postgresql guys did a magnificent job with 9.0 (streaming and
performance). you guys rock.

--
Best regards,
Dragos Moinescu