It's very disappointing indeed and of course, there's no guarantee that everything will be sorted out by next Summer. HOWEVER, the main obstacle - the cause of the US stance - seems to be the US mid term elections in November. Once that's out of the way, some semblance of normalcy will hopefully return.
My main concern, of course, is the Irish situation. Most EU countries' airlines have absolutely no interest in buying into US carriers, so this whole debacle is particularly frustrating.
Ireland did a side deal with the US last year (subject to Open Skies coming into being from this November), but since the Irish agreement doesn't do anything to compromise the competitive position of any other country, it may be able to slip under the radar. With Aer Lingus due to be privatised this September, potential investors will need assurances that it can benefit from new route opportunities as planned.
Even when this US ownership thing is sorted out, there will still be a problem over access to LHR, with US airlines like CO seeking guaranteed access. That could yet cause a further delay.