I recently purchased a used 2015 FJ-09 with about 3,000 miles on it from the original owner. It's my understanding he used it primarily for commuting and very little (if any) touring.  After a recent 150 mile ride through the twisties, I noticed that the rear shock appeared to be leaking and dripping on to the exhaust - hence the smoke caught my attention.  
Has anyone else experienced a similar issue?  Any idea whether Yamaha warranty service would apply?  I'm not overly happy with the stock suspension but I can live with it...at least until I've finished some other upgrades I'm wanting to do. 

That is unusual but for a lay-down shock and depending on the weather and particulate conditions it's not inconceivable that the seal got scored and is now leaking. I have a couple of stock shocks sitting here in a box. Or you could have yours serviced, revalved, and vastly improved by sending it off to Norwest for his magic touch.
 
If the bike is within the original warranty term (or extended) it *should* apply even though technically these are wear parts.

Thanks.  I think I'll start with Yamaha.  If I don't have any luck, how much would you ask for one of your stock shocks?