Ironically, right now TRIM has too much to do with mac, because the support for TRIM is available but only for SSD sold by Apple.
It is still unknown at this point if Apple will extend TRIM support on all SSD with 10.7 or keep it exclusive for their own SSD.
You can extend the trim support to your own SSD with a little hack, but the procedure is quite recent and haven't been tested thoughtfully so backup and use at your own risk.
http://www.groths.org/