Canon's newest in the EOS family.
The Canon EOS 550D is also known as T2i in the US and KISS X4 Digital in Japan. It is seen as the successor to the EOS 500D but with a slightly higher pricetag and much better performance it now comes very close to the 7D and according to DPreview it has better specifications than the 50D.
The 550D has the Digic4 processor and the 18 megapixel to go along with that. The new CMOS sensor is similar to that of the 7D.