In a post this morning at TUAW sister site DownloadSquad, blogger Lee Mathews noted that Opera is the first web browser to make it into the Mac App Store that isn't based on the WebKit core of Safari. It's also the first BitTorrent client to make it into the Mac App Store.
Apple has never been fond of the "special" uses of BitTorrent technology, particularly in the realm of distributing illegal copies of music, movies and software. The company previously shut down an iOS app, Drivetrain, that could be used to remotely control the Transmission BitTorrent application, citing that "this category of applications is often used for the purpose of infringing third-party rights."
If Apple chooses to look the other way on this specific functionality of Opera for Mac, we're wondering if some of the other features -- including extension support and a built-in email client -- might hit the Mac App Store hot button. We'll be keeping our eyes on the Mac App Store to see how long Opera remains available.