I think the Ansett logo does look dated - but then I think it has always looked a bit clunky. All those stars - very 80s. I can understand that you guys view it with fondness because it signifies an airline which you loved, but for many people that look and name signifies a failed/financially shaky airline. (I'm not saying I do, just pointing out the marketing rationale.)
I personally really like the new bmi look, although it looks so 'right now' that by next year it might be looking very 'yesterday'...