Now, question is, how many people will move from OW to *Alliance, essentially QF to DJ? I would be tempted.
As you know I have a foot in both camps of
oneworld and Star Alliance. I'm currently BD*G but I'm looking at other *A FFPs right now since it is inevitable that BD's Diamond Club will be enveloped by LH Miles & More, which I have bucky's chance of making good out of. If the Virgin Group joins *A, that's another FFP to potentially consider, depending on how they reshape the program to fit the alliance terms and cross-alliance earn and burn. The advantage is that, like QF, it would be a "natural" FFP for Australians to join, notwithstanding that the USA based FFPs are admittedly easier to gain status, burn miles and have more benefits if you fly their metal.
My domestic flying habits may well change. For example, if I finish requalifying for
oneworld, I can shift all my domestic to DJ and quite potentially save $$$ (although my experience sadly usually finds that DJ prices are almost equal or more than QF prices, but I guess part of that is down to searching and purchasing strategy), especially if it means *G gets 20 or 23 kg of baggage on GO! or Blue Saver fares for free (or, they may not, viz. NZ Seat fares) plus The Lounge access.
Internationally it's also great because it may give more options for connecting to *A carriers. For example, I could book a SQ A380 flight ex-SYD and connecting flight BNE-SYD on DJ, with full interline and other benefits. Plus, if Virgin Group create their new lounge in SYD, that could be a great lounge that *A needs in Australia (the Koru Clubs for most part are doing an adequate job).
So will I hard defect to *A if Virgin Group joins? No, but I definitely look forward to having more options. Double status does have its advantages (although it does limit your earn and burn capabilities).