Apple will host a special event this month in Cologne, Germany, one day before the start of the Photokina tradeshow. Apple's invitation to the September 24 event is typically nondescript, but it does give a hint as to what the company will talk about.
"Start photokina a little early this year" is the message on the invitation. Below that text is the front of a camera lens — and what appears to be a closeup of the same image used on the front of the box for Aperture, Apple's pro photo post-processing application.
Photokina is held once every two years and focuses on the global imaging market. Apple US and Apple Germany will both be on hand at the show. After looking at the invitation and the focus of the show, it seems logical that Apple will discuss or show Aperture, which first debuted last October.