I'm REALLY curious about this. Will they charge a transaction fee and have it as another revenue stream for them (like iTunes/App store)? Or is it going to be another commoditization of their competitor's/partners products in order to move more hardware (like iMessage). If it's the latter that would be a HUGE deal. I just can't imagine they would be able to resist taking a slice of that $12 billion/day transaction pie, though.