I've never hesistated in doing the maintenance on my cars. I guess it depends on your style of driving and what your longterm intentions are with your LS. Sure the leaking is minor, but come summertime when it's really hot and you're stuck in traffic, you're going to blow your head gasket bigtime. The leaking is only going to get worse. And it's far cheaper to replace the head gasket now than do more major headwork later... plus the fact that you still can control when your car is going to be worked on. Even if you were thinking of doing some engine swap in the future, doing your head gasket now just keeps your LS engine worth something. At 115K, your car has the potential for many miles ahead of it. But again, it's your car and your investment. I would protect it and get the work done.

BTW was your timing belt and water pump changed at 90K miles?