There was a recent thread on whether the "time was wrong for Open Skies" that obliquely touched upon what the net effects would be on the USA, EU and other country's airlines. Rather than hijacking that thread (consensus was that it is not a bad time to start Open Skies) I thought I would start a new thread.
Here is my guess at the ramifications of Open Skies on the markets involved.
1. USA Ramifications: There will be very little impact on most of the USA airlines. There will be the opening of LHR to the previously barred USA legacy airlines, but this will have minimal impact except in getting some corporate contracts. There will be the effect of allowing BA and AA to get OW alliance anti-trust immunity to compete with *A and Skyteam on TATL co-operation. While these changes might be noticeable for the USA airlines, they will not be earth-shattering. There might be some consolidation among the USA legacies, but it will not be driven by the Open Skies changes, as most of the EU countries already had open skies agreements with the USA. There might also be a bit more competition from some other large EU airports from other EU airlines, but I don't foresee anything astounding.
2. The big changes will be on the EU side of the equation. I think that there will be much more consolidation by the EU's legacy national carriers. As any EU carrier will be able to fly from any EU airport to any US airport, we will see many of the smaller countries' national carriers that don't have the necessary economies of scale swallowed up by the larger EU carriers and relegated to "Focus Cities" with limited TATL service to large O&D or partner hubs. There are 16 or more legacy type carriers in the EU as compared with 6 in the USA (Similar sizes).
3. The EU consolidation will also be driven by reduced connecting pax revenues, as more points from India and SE Asian countries are able to fly directly to North America without transiting EU airports. The USA airline will not see much difference as the drop in their 5th freedom revenues they will be able to offset by providing the non-stop service. There are no equivalent connections from the EU through the USA to anywhere substantial.
To sum up my view:
1. Open Skies will have minimal impact on the USA airlines other than the increased competition at LHR and perhaps a few other large EU airports.
2. Open Skies will drive a large reduction in the number of EU legacy carriers through consolidation (and perhaps liquidation), turning many of the smaller EU capitols from "Hubs" into "Focus Cities".
Looking at this, the business case for the A380 might be bolstered by Open Skies.