So finally there's a deal it seems. You'd have to be brave to predict what will happen next - but a sensible analysis needs to start with alliances. (And then look at the people not in alliances.)
At Heathrow, Star Alliance's day could have finally come. I'd guess they already have a plan ready to go for how to leverage the slots held by BMI, Lufthansa, SAS, and United.
For Oneworld, with the non-immunised alliance between BA and American, things are more complex. But all of a sudden Iberia is more important than ever - and unsurprisingly merger rumours have come from nowhere as the open skies deal has looked inevitable.
Skyteam has even more wrinkles to its situation, but my feeling is that they've already thought it through. Delta's move onto JFK-Gatwick was a real strategic step, and Air France's refusal to become embroiled in the Alitalia meltdown has been unshakeable even at the opportunity-cost of not moving into Malpensa. Continental, with its tactic of what has been described as 'carpet-bombing' Europe with 757s also looks a whole lot more important.
And remember, Skyteam already has its hands on Heathrow Terminal 4 once BA moves out to the new T5.
But non-aligned players will hold the key to some markets. The 65-ton gorilla is Virgin Atlantic of course - which is not happy about the intrusion into its Heathrow domain, but has a world-leading track-record in establishing overseas operations and the brand to end all brands. Sir Richard's creativity is going to be challenged as never before.
Slots of course are likely to soar in value, but where will they all come from. One source I think will be small, government-owned, flag-carriers - Air Jamaica just as an example - which will be sorely tempted to take the cash and hand over the routes to codeshare partners to fly with 'their metal'. In some cases they could then get expensive widebodies off their books.