The event organization site is clearly designed for a crowd looking for a simple online planning experience rather than the Web 2.0 maximum, as well as those looking to collaborate with other community members. It evolved out of a project called Fatdoor, shaped by user feedback that (among other things) changed the potentially offensive name.
As with its Fatdoor predecessor, Center'd aggregates local business ratings and reviews from Yelp and MenuPages and lets members tag venues. There are a few new features that the likes of Upcoming haven't come up with yet, and most of them deal with group-organized events. If you're not sure when or where to hold an event, for example, you can provide a handful of options and let your guests vote. You can also put out a call for volunteers and specify exactly what they'd like you to do.
But Center'd, from what I've seen after playing around with the beta version, doesn't offer nearly enough to make it a truly worthwhile entry into the "event site" niche. That said, it's an easy-to-use site with a clean interface and stands a chance of appealing to the luddite niche.
Indeed, the site doesn't even classify its early phase as a "beta," opting instead for the decidedly lower-tech "first draft."