It's not piracy, lol. MacHeist has been around for quite a few years now and developers opt-in to the program. Although, I don't remember a year that they offered the bundle free, or am I forgetting?
This isn't the main bundle, and they've been known to give away small collections of apps before, e.g. the Giving Tree at Christmas time. They also give away a ton of free apps for participating in missions during the actual Macheist events, so free software from Macheist is certainly nothing new. They had a small event a week ago on Halloween as well, so I'd say they're just gearing up for some new big event (MH4?) or some holiday special and are using these apps to draw attention, stir up press, and get people coming back around to the site.
