I replaced my mainseal and o-ring in March 2010 at 99K miles ( see the end of
http://k11og.org/forum/viewtopic.php?t=8251&highlight= for details). I didn't have much of a leak but enough that some got on the clutch and it started acting up when engaged. Also brought the trans into the shop and had them replace the seals while I had the trans out. At the time it looked like the issue was the o-ring and not the seal itself, but of course I did both.
4 years and 29K more miles (6K this year)and not a drop of oil or any related issues.
Today I went out to fire it up (it got about 30 degrees here) as it has been on the centerstand since my last long ride in October. It fired right up as usual but I noticed a puddle of oil (maybe 2 ounces) right under the weephole, and a drip forming at the weephole.
Any other culprit I should look for? I am not that excited about doing the mainseal again (although it will go easier the next time, swapping the one piece stock pipe for a 2 piece Remus makes everything easier.