I posting this just as a statement. I really liked the new look of Blender 2.3, but since i work with a 2 button mouse, the functions of zoom, pam and rotate view is not working. I’ve checked my preferences for the simulate a 3 button with alt, it is pressed, but not working. I hope it will be back, since i am used to the 2 mouse button.
:o
A 3 button mouse w/wheel is industry standard, one of those obviously better upgrades. They’re really cheap and almost everything is geared for them. You’d be doing yourself a big favor by getting one and Blender will be just one application in several that will be easier to use.
once you go wheel
you never go back
haha
i got one too, i HATE working without it now
(now for an optical mouse)
After four years having a four button track-ball, blender 2.3 forced me to activate the third button. Suppose the 4th will come in about 2007. I’m courious. 
if i buy my dads awesome 5 button mouse with 2 scroll wheels, will i be able to set up the extra buttons so they work with blender?
you can parent the buttons to keys, so i could have one button was extrude, or spacebar, but would blender reckognize it?
Not in blender
though i would think trying the drivers would be worth a try. (the intellimouse drivers for microsoft mice let you do that, but I don’t know if it works with blender)
It’s a bug, should be fixed soon.
Finally, I decided to activate the forth button and it does work with blender.
My driver only comes with a set of presets but F-buttons, Ctrl, Shift etc. work. Have to see what’s best.
Spacebar can be “emulated” with holding RMB and press LMB or MMB.