Just as a heads-up regarding the TRIM/RAID thing - this is not dependant on the drive manufacturers supporting TRIM in RAID. It is the current generation of RAID controllers that do not support TRIM, and cannot pass the commands through to the drives. It may be the case that such use of TRIM will never be supported in a RAID array, since it adds a lot of complexity on both sides (as drives decide where data goes due to wear-levelling etc, the controllers can't tell them which bits to 'TRIM', and as the RAID controller splits up the data between the disks the OS can't really tell the drives where to TRIM either). However, with new controllers such as the Micron supporting more advanced forms of garbage collection and other automatic cleanup options it may be that TRIM support in its current form is not required anyway.
It is also the case that, although RAIDed SSDs do bench higher than single disks, the real-world performance does not really change that much. The near-zero access time of a single SSD is what is important, not whether you get 200MB/s or 400MB/s sequential read speeds. The higher maximum speeds are not really an issue at all for OS-type use especially, so no real benefit is seen when you go from 1 disk to 2.
However I do still have to question the need for 99% of people to have a 250GB+ SSD though. You can get 90% of the performance and much more capacity for much less money with a smaller SSD backed up by a RAID0 HDD array. Since it is easy and cheap to build high sequential speed mechanical arrays it makes sense to only use SSD where it really shines - random use. With 3 good hard drives in RAID0 you can blow away SSDs for capacity and speed and still save money providing you use them properly - for sequential access (such as you measure when you run a straight HDTune benchmark). Many larger games will load similarly on a 2-3 disk RAID array as they will from an SSD, especially if you have the OS on a separate drive so the RAID can concentrate on getting the large, sequentially read texture files into system memory.
Edited by the_beast - 2/14/10 at 2:22am