I'm considering upgrading to SSDs from my raid raptors.
There's really 2 disks I'm concerned about - my OS/apps partition and my games partition. I don't want them on the same partition as I frequently reformat my system, and I want my games to stay the same.
Should I get one 80GB X25-M and partition it into two? Or get two 40GB X25-Vs?
Also, does partitioning an SSD lessen the lifespan of the drive?
Partitioning won't have any effect on the drive's lifespan. The biggest impact on lifespan is simply how much free space you have - the more freespace the less frequently the flash memory blocks will need to be overwritten, and it doesn't matter if the freespace is in one partition or two.
Personally I'd probably go with the single larger drive since that gives you more flexibility with partition sizes (40/40 or 30/50, for example).
In theory you might be able to get more concurrent I/O out of two drives than one, but in reality it might be a wash if the 80G is a better performer to start with.