Though I would love to see the 717s here in Australia, I fail to see where they would go... Sure if QF weren't bringing in truckloads of new 738s there may be some place in the market, but as (from other comments) the 717s don't have the same field performance as the 146s, this would exclude them from many regional WA routes for example. Hence they would have to hit more major routes.
I have heard from my impulse-employee cousin that CBR is set to be a base replacing Southern 146s. This is no surprise but would be a 2 plane op, 3 at max. The other rumour from him is a high freq. ADL-MEL, but I find this quite difficult to believe, considering the need for a business class product on this route... but perhaps I am wrong on this???