I still want to see Ashoka survive and appear in the live action show. I don't think Anakin could bring himself to kill his old padawan, which is how I would explain her survival.
First off, it was the Clone Troopers who killed the Jedi. It wouldn't have been Anakin's call. Second -- the guy murdered a large number of children. If he was far enough gone to do that, I can't believe he'd retain any sentiment for Ahsoka.
I'm not an expert on the EU but didn't it establish that Vader personally hunted down Jedi that escaped the initial purge? And sure you could argue that he wouldn't spare her but if somebody wanted her to survive there are worse ways to do it.