No, they don't support TRIM any more than your onboard RAID array does.
All they are is four Vertex 2e drives in RAID 0 on a RAID controller, but all packaged on the same unit to save space.
Honestly the extra expense over building your own Array isn't worth it, unless you have some specialist application which requires better sequential throughput than the 600 or so MB/s your onboard ICH10 can manage.
For normal use and gaming the storage bottleneck is pretty much eliminated at one SSD, never mind four. Your money is better spent in getting more Gigabytes than faster throughput.
Of course, if money is no object, by all means go ahead. It looks cool and saves you a couple of minutes of fitting and cable managing 2.5" drives.