Nice to see some informative, non-flammatory, non-nationalistic posts here! Just objective & fair analysis of the situation.
The UK will come under ever-increasing pressure to strike a deal wit the US in my opinion; if it doesn't, it risks having the EU interpret "Open Skies" for it, and BA losing out in a very dangerous way by not allying with American, in a way that AF/DL have been able to.
Open Skies is not a completely liberal agreement, there are still some restrictions which I think could be lifted. Although a lot of people have poo-pooed cabotage as unecessary & symbolic, I still think it should be granted, if what we want to do, is fully liberalise the "air" market for the benefit of the consumer (that's the aim isn't it?).
Seventh-freedoms should also be granted; the UK in practise only secured a few such freedoms from the US.
The "substantially owned and effectively controlled" clause should also be removed. Any airline, regardless of who owns it, should be allowed to operate any service to the US, from any origin, to any ultimate destination country.
Some may regard the above as unecessary, but I beleive we should aim to remove ALL and I mean ALL barriers to promote true competition; and who is to say a future or present airline won't use cabotage or seventh-freedoms?
And there are also a few other niggly issues which I have already mentioned (re:Atlas Air and leasing of American crews to other operators-not reciprocal), personnel on US Gov't contracts obliged to "fly American" etc., but I think these should really be left alone, in the interests of the greater national good that Open Skies will bring to the UK (and the US).
And obviously the Americans have much more to gain out of this than the Brits, but it's not exactly their fault that their geographic market is so large.
And lastly, as someone has already mentioned, the UK and the US are presently on "best buddy" terms, so this is the perfect time for a bit of arm-twisting & ankle squeezing (if y'all see what I man by that)
Open Skies is possible, if both parties are prepared to make a little compromise (if it is neceessary).