Tire not balanced? Had a buddy that had a high speed wobble at 120+. Ended up being last place that balanced, used the little ball bearings inside the tire (dont know correct term), instead of the wheel weight method. This was also multiplied by having a heavier compound tire (Shinko I believe).
He replaced front and rear with PP2ct's, balanced and problem solved.
What kind of tires?
Over-filled brake reservoir can cause similar problems, especially if you just bled the brakes.
P.O of my bike did the same thing, pulled some fluid out and it went right away.
Dynabeads work well too, professional shops should be able to balance your tire appropriately too.
'06 in Silver: 29K on the clock (and counting)
PCIII w/custom tune (stock AF and shortie stacks)
320mm rotors with SBK5 pads, Galfer HH rear
Full f/r FenTubo Type 2 set black on black
Nissin Radial M/C (07+)
wrapped in Mich Power Pures (aka love)
My first thought would be that the front wheel is balanced incorrectly. It's most likely down to loosing a balance weight as already mentioned or the correct weights were not applied when the tyre was changed. At the very least you might want to remove the front wheel and check that it is balanced.
Could be a lot of things. Break the bike down and check the front end. Steering head bearing, Front wheel bearings, Front wheel spacer missing, bolts/nuts not torque'd correctly, front wheel not balanced properly to name a few, bad tire, bent/warped rotor etc
A loose or bad steering head bearing will not cause "wobble."
You would know if the steering bearing is bad as soon as you apply your front brakes. It would make a "clunking" sound and you will feel the movement.
Have you removed the wheel yet, and checked your spacers? Checked to make sure you still have a balance weight?