Sean,
The seals won't turn into an ecological disaster anytime soon.
When the bike warms up, the cylinders/heads move and expand slighty, which, when the seals are new and soft is easily dealt with and there are no leaks. As they age and harden, they are no longer able to seal properly, as they're just too hard to flex enough to maintain the seal.
They will weep for many thousands of miles, very gradually getting worse. Weeping for 10,000, even 20,000 kilometres is no surprise.
They are easy to replace when it comes time. And if someone suggests banging on the collar just above the seals on the pushrod tube, it won't work on yours. It worked on approx. pre 1980 models only - and then temporarily.
Don't worry about it until you have an opportunity to deal with it easily.
Note - if you have the topend off for any reason it's worth replacing these, as well as the o-rings on the studs. They aren't expensive.
------------------
Grant Johnson
Share the Dream!
at:
www.HorizonsUnlimited.com