The weight is in the panasonic G3 class - amazing. And the lens mount looks h-u-g-e!
Yeah, here's a comparison to the other smallest Rebels of the past (XTi and XS), sorry I was too lazy to resize the pictures:
EDIT: On the opposite side of the spectrum, here it is in comparison to the EOS M and EF adapter:
Looks pretty much like an EOS-M with a prism housing - size wise.