Brooks said:

SilverWook said:

It's been speculated Vader prevents Boba from shooting Chewie in ESB because Threepio is on his back, but that's a stretch. A Dark Horse comic does have Vader recognize him, and he gives the order to have the blasted droid put in the cell with Chewie.

I have wondered if Artoo can see Obi Wan's ghost...

Vader is ok with killing younglings, a planet full of people, his old besty Ben and his own son (the last remaining remnant of padme) but he's sympathetic to a droid that he left without hesitation as a kid?? I dunno...

Well, he did get him back in Episode II. ;)

There is an interesting passage in the novel where Vader reflects on the destruction of Alderaan. It almost borders on regret, until he reminds himself the planet also had traitors to the Empire living on it. Whether Alan Dean Foster invented that internal conflict, or got it from Lucas is a mystery.