Tim has a good point about bleeding the caliper... You'd need to do it right way up then turn it over, and it might still have a tendancy to gather air in the pistons- though of course a well bled system won't have any air in it anyway.
It seems to be a fairly common mod with the wee Brembos for US race bikes, but they're either not very functional, or butt ugly, and no room inbetween. Sid's right that you'll be left with the torque arm mounting on the wrong side, which is going to look rotten... But it should be relatively simple to brace it, since the rotational force would spin the caliper towards the swingarm- it's easier to brace for pushing towards than it is for pulling away.
It's an interesting idea, but the skeptics win
Unless you were doing it with a totally new caliper and bracket, it's never going to look better than a bodge IMO.