Check for steering head play- involves lifting the bike up so that the front end is free to move, and moving the wheel by grabbing the axle to see if there is any play, front-to-back and side-to-side. The other thing to look for is to compress your forks (once it's all back on the ground!) and listen and feel for a "notch". You'll also want to check the nuts and bolts holding your steering head together.
15000km is about time you might think about having the head bearings checked, if not replaced. Typically motorcycle manufacturers use normal round bearings in their races (races in this context meaning the rings that hold the bearings in place), which eventually form a groove due to offset forces. If this is what you have (as most bikes come with this for upper bearings at least), then consider tapered roller bearings. The bearing assemblies themselves cost between $10 and $30, and you'll want to replace both upper and lower at the same time.
You'll want a reputable shop to do the work, as removing the bearings from the frame can be tricky without the proper tools, plus it's soooo easy to hide damaged goods in the steering head
Skim through this linkto get a better understanding of steering head anatomy, and what's involved.
don't have a baggy myself (strongly considering getting one soon) but I've had the steering head prob on a sportbike and had it sorted by a professional suspension shop.