If you are in the United States (you signed off in German, so I'm not sure) make sure you look into the Canon Loyalty Program for your purchase of either the 60D or 7D. Through it, the 60D is available for $640+tax and the 7D for $1080+tax (both refurbished by Canon). This will save you hundreds off new!
As a 60D owner, I use my pics to run with my stories in a weekly paper owned by a large publishing company. Our budget is tight and we have no full-time photographer. My Nikon D40 wasn't cutting it for my specialty, sports. I shoot a lot of evening field sports (football, baseball, lax, and more) and some indoor sports like volleyball and basketball.
The 60D was endorsed by another POTN member I've known since high school. He recommended it due to the affordable price point, ease of use, and low-light shooting ability. The 5.3 FPS I get out of this camera is adequate for sports, but the 8 FPS of the 7D would be even better. I have no issues whatsoever with the 60D, though. So far, this camera has been spot-on for me and his recommendation was perfect. I also shoot some landscape and portrait, and the 60D is solid there too.
A number of my photographer friends use 7D's as either their backup camera or their dedicated sports camera. One of them has a 5D II for landscapes/portraits, the other a 5Dc for weddings. Both love their 7D's.
I find the articulating screen to be a game-changer, and that will keep the 60D in my bag for awhile. I had to take a few over-the-head shots today at an event I was covering to reach over the crowd. Also, the 60D is insanely easy to use coming over from the clunky Nikon D40. The 7D requires more learning and customization, but that doesn't have to be a bad thing. If you can live without the articulating screen and you'll be shooting a healthy amount of sports, the 7D is hard to argue with.
From an image point of view, or how other pros perceive you, the 7D seems to be accepted as a very capable body in sports circles, journalism-style shooting and even for weddings. The 60D has never made anyone laugh at my face, even if 40D and 50D owners here regularly come out of the woodwork to call it things like a "plastic toy" or "super rebel". With a battery grip attached, the 60D's profile isn't so different from a 1D. From 15 feet away, you look the part to anyone but the most bitter camera snob.
Again, the game-changer is the articulating display. Not only is it handy for shooting over the head and below the knee (or around a corner), but people around you will ask to check out what you are shooting when the high-res screen flashes a pic. I was at a spring training baseball game last month when a baserunner was called out stealing second base. I happened to get a shot of it from the upper deck behind home plate with my 100mm/f2 lens. I cropped to second base to reveal the runner was out by about a foot, and showed it to the disbeliever two rows behind me. It was nice to prove i was right that the runner was out, yes, but it was an even better feeling that I got that great of IQ out of my camera/lens combo.
The 60D and 7D use the same sensor and have the same max shutter speed. The 7D has better weather sealing, although the 60D has some. The 7D's faster shooting and AF system, with MFA, is its trump card. The cameras have the same IQ, just the 7D's superior AF and MFA give you two more tools to help you produce the best image possible.
Good luck, you'll be getting a really great camera for a good price either way.
Sony A99ii, RX-100ii, Sonnar T* 135mm f1.8 ZA, Planar T* 50mm F1.4 ZA, 24mm f/2 SSM Distagon T*, Minolta HS 200 2.8 APO, Minolta 2xTC APO, HVL-F43M