If you have a BlueTooth mouse with a scroll wheel, please quick try this out:
http://graveck.com/test/ScrollTest.html
Click on the Unity content window just to make sure it’s getting events, then move your mouse’s scroll wheel. The number should change. If it doesn’t, please tell what mouse you are using.
Basically, this doesn’t work with a wireless MightyMouse, and I’m trying to get it fixed.
Thanks!
-Jon
-Nevermind
Thanks for testing!
Is this the mouse?
http://www.logitech.com/index.cfm/products/details/US/EN,CRID=2464,CONTENTID=10716
It looks like it is not a BlueTooth mouse, but something proprietary where you plug in a USB transceiver to your computer.
-Jon
Hi Jon, using a bluetooth mouse with the test player, it didn’t respond to wheel scrolling.
Using this mouse here;
http://www.trust.com/products/default.aspx?item=14231
It was the only mini form factor bluetooth mouse i could find that didn’t include a receiver (don’t need one on the MBP) and had a switch to turn it off when not in use. Despite the lack of printed OSX support, I find it works reliably when traveling.
Adding, USB wireless mouse (Logitech) worked fine in the test player.
Hope this helps!
Im using a wireless Mighty Mouse (A1197) and it worked ok.
Strangely it didnt pickup the scroll from the touchpad though.
Ive currently got a problem where the scroll sensitivity between a mouse and touchpad is wildly different (the mouse moves in microscopic increments and the touchpad moves in large ones)
Could be related.
Cheers
Shaun
Using a usb wire (not less) microsoft mouse (I know, I know… mighty mouse is broken and I found that mouse in a drower…) all is working!
Ok, I know you don’t asked that but you can’t exclude me from this game only because I don’t have a wireless bluetooth mouse! 
Doh, I just read it as wireless mouse for some reason. Shrug.
Kensington Bluetooth PocketMouse (or whatever); scroll wheel doesn’t provide any input.
For anyone checking different peripherals, make sure you re-open the player before using them. Unplugging a mouse while it’s running won’t let it work with the trackpad (in my experience).
Works in the beta web player for me and a MS mouse.
BT Mighty Mouse here - numbers scroll just fine.
With all of your help I think I have narrowed it down more! 
If you have two mice, (or have a trackpad and a bluetooth mouse) the scroll wheel only works on one of them. I have gotten a bluetooth mouse’s scroll wheel to work when I disconnect the USB one.
So, it’s not that big of a deal, except for laptop users who commonly will have a mouse attached.
-Jon
Ahh good to know. Thanks Jon for shedding light on this limitation!
(/me wonders now what we can do about it… heh)