The biggest issue is the cost. They are rediculously expensive for what you are getting in gain. Remember, a SSD will only decrease load times. So if you are looking for a gaming gain you'd be far better off upping that GPU, even to dual high-end graphics before going with SSD.
Does it really matter if you load a single player level in 15 seconds compared to 30, or zone in WoW in 6 seconds compared to 12? Or will it matter that you are running double the framerates all the time?
See the other thread for more discussion on 'better ways to get an increase for the money'.
If you peep my sig, you'll see that only the very most expensive 2 (of I believe 8 builds) have SSD drives.