If you want a lower idle temp, you can change your fan speed manually via RivaTuner or MSI Afterburner and have the fans always at say 65%. It's louder, but will keep your idle temps right down. Also yeah.. what Tamz said.. your card can take much hotter than that so not to worry.
Nahh. Your fan should be rated to last for like 20'000 hours at 100% or something like that. Meaning you will have at least a couple of years before you have any issues.. and even then.. as long as you clean the fan once in a while you'll be just fine.
I run my GTX 260s at 72% constantly, have done for around 10 months now, and have no issues what so ever. Same RPM and same noise as when they were new.. just remember to clean them once a month or so.. just blow on the fan or wipe with some tissue etc.