Aethelred is a once common English name and I don't see that one making a comeback. I haven't heard of any Cnuts or Ragnars in awhile. Can't say I've known many Margarets or Ruths.
Must be an Aussie thing, but we get some Ruth's these days.
Seems generally some of the old school girls names in particular are back in vogue. Charlotte was mentioned somewhere here, and that's another one I see quite a bit.