I too would like a nice multi-button bluetooth mouse, but I haven't found anything so far. I have tried the MS Bluetooth Mouse, Logitech MX900, The Mouse BT and the BlueTake BT500, but keep going back to the single button Apple one.
I wan't too keen on the huge MS/Logitech ones, but the thing I really couldn't live with is the short (a few days) battery life for their rechargeable batteries. This might be fine if you are using it on a desktop machine and pop it in the cradle each night, but given the 2+ months of use I get from good AA batteries in the Apple mouse it just isn't good enough.
The Mouse BT just feels cheap and nasty, looks similar to the Apple mouse... that's all it has going for it.
The little Bluetake Mouse was the closest I came to finding a winner, but I just couldn't deal with the small size. I have never liked tiny mice, corded or otherwise.
I suggest looking at the
Bluetake BT500 if you like small mice, otherwise I'd stick with the (no longer particularly expensive) Apple option.