I'll tell you what I did: I got a Logitech DeNovo for Mac keyboard (not the "edge") which is wireless, but needs a usb dongle (not bluetooth); it has a bunch of cool functions overlaid on the top row function keys: brights +/-, F3-F6 used for various expose/dashboard toggles - you get to pick which ones), media control buttions, volume up/down/mute, eject, the four app buttons F16-F19; again, you pick the apps, the defaults are itunes, mail, safari, and calculator.
I like it quite a lot, and I prefer the traditional keys rather than chicklets. But, YMMV. Anyrate, with that keyboard, I don't miss the middle button or the squeezy side buttons on the old Mighty Mouse.
Eddie O