So I went for a ride on Thursday and I noticed two things:

First, at about 70mph my bike vibrates so much it blurs my vision (I don't think it did that before. Haven't ridden in about forever because of my job and the friggin' weather in Seattle sucks)

Second, when slowing down to a stop with the exhaust at it's quietest I hear a whirring sound that stops when I stop rolling (would that be the stupid, unneeded middle drive that Yamaha in their infinite wisdom thought they should put on so something else could break)

Are the wheels properly balanced? Just like a car that will shimmy at a certain speed range; the bike can have a critical speed where an unbalanced wheel will bounce worse than at other speeds.
The whine is probably wheel bearings. Unless the transfer case (middle drive) has gotten low on oil the chance of it havng any problems are relatively slim.

Clifford

I haven't changed the tires or anything, unless they didn't come from the factory balanced. It doesn't feel like that anyway I've ridden a bike with out of balance tires before and it wasn't like this. All I know is I wouldn't want to ride very far with this vibration 50 miles was enough for me.

Is it vibration or wind buffeting? My vision is blurry at highway speeds too but it's from buffeting.

I went to Wal-Mart vision center and bought a pair of prescription sport sun glasses. They have a rubber gasket between the frame and your face and an elastic cord that tightens around your head. It's like wearing goggles. Now I can actually read road signs at speed! No Blurr!!

Not sure I can help you with the blurred vision but the 'whirring' sound you're hearing is probably the front breaks. With the holes in there and the pads. . . .friction!

One time I was changing out my boards for forwards, after finishing up, I put a few extra tools in the roll up pouch under the seat, It was just enough to transfer the vibes into the seat. Took me a while to figure that one out...

The whirring sound comes from the belt being misaligned. I was at the yamaha dealer and overheard a conversation between the customer and the service manager. The belt was frayed on one side and the service manager told the customer that they have bikes out ther with over 100k miles on them and the belts are fine. They checked it all aout and found that the markings on the rear swing are are incorrect. They performed an alignment on the rear wheel and that seems to have fixed the sound. If you are coasting the sound is more perciptable.

well this is my little input might be might not be..

for the vibration that you feel.. since it has been a while the tires might have a flat spot in them from sitting and after a nice long ride to heat them up they should round back up.. my convertible does that but only if I don't roll it in the garage to move the wieght of car to different spot on tires..

the other guys have good places to check for the whirring sound.
the belt might be to tight or out of align.. both easy to see and check. You can see if its out of align by looking at the pulley I used to use the bike jack and roll the wheel forward and backward and see if it was moving from side to side.. No jack just walk it back and forth a bit and than look.
Too tight and you can't twist it at all, I know they have a method here for proper way.. It only needs to move a little up and down to be right, and doesn't like to move at all when wrong.

Vibration? Mine has a shake, at a certain rpm. If I cruise at or near 60 my lower wind deflectors look like a humming birds wings. And also in all the gears at a certain rpm... just took it to be normal for these bikes, am I wrong??