Really cool news. Thanks to sponsoring from AWeber.com, and code by OmniTI's own, Brian Dunavant, OmniPITR now supports additional tablespaces in backup creation.
This works on both master and slave, and happens automatically without any kind of user interaction or changing options – OmniPITR simply detects if you have additional tablespaces and backs them up to data tarball.
More details are can be found under TABLESPACES in the omnipitr-backup-* docs.