A DSLR is not the ideal camera for street photography. Can it be done? Sure! But it is just too big and bulky and does not allow a photographer to be discreet.
I'm an example of a person that switched from the T2i to the x100, but I don't think the camera changes things that much here. In fact, my best pictures were taken with the Rebel. There are people doing great street photography with Canon DSLRs. Check this guy out: http://www.flickr.com/photos/dirtyharrry/
If you think that buying a Leica will turn you into a great street photographer, you are wrong.