User blog comment:The Milkman/Extended Expectations, Part II/@comment-4939034-20120628162507/@comment-1221773-20120628231814

After Shepard is hit by Harbinger's beam, whatever armor you had equipped is replaced by the same charred version of the default N7 armor.

I'm also pretty sure that a BioWare dev confirms somewhere that the cutscene does show Shepard. Even if that wasn't the case, it would be a big stretch to think it could be anyone else. Why would BioWare add in a cutscene that shows an anonymous N7 soldier surviving (whose gender is the same as your Shepard's) instead of Shepard? There would be no sense in it.