I would get a good set of tires (general consensus), like Michelin PR2's or 3's, and with proper Air Pressures of 40lbs Front 42lbs Rear and see what happens.
I don't get ANY Wobbles or Cupping with these tires and others generally don't either.
Save your money and get good tires first...and as said above...HeliBars for Comfort.
I do have PR2's front and back and I'm pretty anal about the tire pressure. I run 38 front and 40 rear with 1 up and 39-40 front and 42 rear with 2 up. I adjusted the suspension settings last year re: the suspension thread on this forum and it did help with many issues in cornering.
The PR2s are not cupping bad yet but the front does feel like it has a bit of a ridge starting and there is a little wobble particularly when letting off the throttle and taking pressure off the handle bars.
(HaulinAshe noted that some areas with Birms/Uneven Roads will exhibit this characteristic)
Could the wobble issue be due to an out of balance front tire?
(YES, mine did when it was.)
Not sure why it would gradually start now?
(As the tire ages and the tread shrinks...some of these things show up)