Credit: Jamie McCarthy/WireImage

With the American Idol finale but mere hours away, who, besides season 7’s Top 12, will take the Nokia Theater stage on Wednesday’s two-hour results show extravaganza? Simon Cowell’s pride and joy Carrie Underwood, who seems to never turn down an Idol request, was announced as a special performer, and we hear disco queen Donna Summer, rock legends ZZ Top, and teen sensations the Jonas Brothers (pictured) are also on tap.

Idol finale billing always seems to follow a policy of last-minute announcements. By virtue of the show’s live format, it also favors pre-taping, like last year’s performance by Green Day of John Lennon’s “Working Class Hero.” Considering this season’s ratings dip, however, we wouldn’t be surprised if there is a surprise or two thrown in.