TRIM's primary value is preservation of performance as the disk fills. If your environment doesn't support it yet, you can stop-gap it by leaving a few percent of your disk space unallocated, giving the internal block allocators breathing room.
It's not perfect, but it is easy to configure and can make some difference without the reformatting hassle.
I guess the general setiment is that even after a while of using it the ssd will still be orders of magnitude faster than your spinning disk. Doing an Xbench report on my ssd and my 7200 500gb seagate is laughable. One thing you should worry about is the damn thing being too fast and saturating the sata channel. I have a late-2009 15" mbp and it has a poorly implemented sata. If you do the fw upgrade to 3Gbps your drive will most likely not work unless you either get lucky and have a newer revved logic board or downgrade the fw to 1.6. I had to go this route. Email me if you need the link to the fw.
Some blogs says that the "easy fix" for lack of TRIM is to just backup/reformat/restore your SSD every X months. Eeech