I would be surprised if ToroDB implemented the oplog which Meteor uses for efficient live-updating, but I guess it _should_ work with the polling mode.
SQL support (i.e. direct Postgres support) is on the Meteor roadmap for post-1.0.
It hasn't been tested, but as soon as the full Mongo protocol is supported, it should work exactly the same as Mongo does. Give it a try and let us know! :)