sadly not I fear.
Hi, been looking at these and i don't think this kit will work with a mac.
It isn't actually a midi drum kit, it's windont software just pretends to be midi.
If you CAN get it to work - i will buy one in a flash as its the cheapest by half.
But I fear it won't.
Even if it is - i don't think garageband (unlike say Reason) lets you assign midi keys so you wouldn't be able to swap pads etc.
I have an excellent Axiom 25 keyboard with 8 touch sensitive finger pads that i use to input basic drum patterns, If i had £500 there are proper midi kits out there, but the Ion isn't one of them.
Hopefully they will make a mac-ready version (i have emailed them).
Good luck.
Sadly your only way to get it to work on the mac is boot camp and using MS 'sound recorder' to record your efforts to import into GB
A faff too far?