That list is awfully short: It has the same sensor resolution and the same video modes. That's it. The sensor isn't the same (can't be because the 7D has 8 channel sensor readout and the 550D can't have more than 4 channels as it only has one single Digic IV. Not even the center focus is the same (contrary to your belief), the whole focusing array is that from the 20D.
The list of shortcomings is long, very long, the 550D only has (all listed specs are better on the 7D):
■a pentamirror viewfinder (7D: pentaprism)
■95% coverage viewfinder (7D: 100%)
■a 87% magnification (7D: 100%)
■19mm eye point relief (7D: 22mm)
■no electronic level (7D: Yes)
■no grid on demand (7D: Yes)
■3.7 fps for 6 frames (7D: 8 fps for 16 frames)
■only a single cross type AF sensor at the center (7D 19 cross type AF sensors, 3 with extra precision)
■only 9 AF points (7D: 19)
■the singe Digic IV has to process the images and calculate AF positions (7D: 2 Digic IV to process the images and an extra dedicated AF CPU).
■no macro focus mode (7D: doubling of focus position calculation speed to 60 calc.sec)
■flash sync of 1/200th (7D: 1/250)
■no flash master built in (7D: Yes)
■built in flash FOV coverage 18mm (7D: 15mm)
■no PC-sync connector (7D: Yes)
■no weather sealing (7D: Yes)
■no free selection of image formats to go with RAW (7D: Yes)
■predictive AF up to 10m (7D: up to 8m)
■no coupling of metering and subject detection via AF sensor array (7D: Yes)
There may be further differences but the ones listed should suffice to show that the 550D is an entry level camera which just shares some superficial resemblances with the 7D (both are DSLR produced by Canon)...