It fit's a:
Canon EOS 550D with Canon EF 18-200mm
Canon 50mm 1.8
WalimaxPro 8mm Fisheye
Diffusor for Canon Speedlite 430 EX II
Crossfilter Ø72mm in original case
Canon Speedlite EX 430 II
It's possible to get a Canon 75-300mm in the bag too.
All in all it's an awesome Bag for Photographers. It is comfortable to wear it and has a lot of benefits like the little pockets for Cards or remote Control, batteries for the Lightning etc.
Here's a little summary (in German) about the Bag: [link]