Having reflected a little more on this, I'm looking at the positive

AG status never did much for me really - ok, a few extra miles and PE checkin, but I'm sorry, it's been good....
I've enough miles now to do one more trip for the family in UC if I can get the reward availability (which seems to be getting harder), and I think will gradually move over to the dark side after that.
I'll never reach any kind of status with BA, but the one I can reach with VS doesn't do much for me anyway.
I do like flying VS, but it's only a few hours out of many days holiday, so this must not get out of proportion.
BA superior network, equal(ish) AMEX card, easier reward availability and redemption --- and miles for children plus household account --- well, that's it.
I've three more return flights already booked with VS, and after that, the shackles are off - I will look further affield.
In a way, this announcement has done me a favour, and made me take a long hard look at why I "through my lot in" with VS, and I will be moving on now, I'm pretty sure.
The other attractive feature for me was the PE offering - which I first experienced in the bubble, and it's rather coloured my view ever since - economy with BA? Yes, I can probably better afford the holidays and can "treat" the family to a WT plus every now and again.
I may view this differently in Nov/Dec once my current flights have come and gone, but for the moment, my brain is saying "that's probably the end - so long and thanks for all the fish", and back to BA I go...