It's a lousy outcome for the British, who are now locked outside the doors of the next stage of European integration. It's not quite equivalent to 1955, when the UK walking out of the Messina conference which set up the EU thus ensuring that the structures would be set up without Britain. But Anton La Guardia had a point when he said on Twitter that "at least Cameron cannot be accused of being Chamberlain. He has no piece of paper to bring home".
On 18 November Cameron met with Merkel in Berlin, and set out his price for signing up to a new treaty: i) Britain should be allowed to revert to its opt-out from the social chapter (as the previous Conservative government did), ii) unanimity should be brought back for decisions concerning financial services, and iii) any new system should include an "emergency brake" which non Euro Area member states could apply if and when they felt that decisions by the Euro Area threatened the integrity of the EU as such. There was never any chance of getting Germany (or indeed most other EU member states) to agree to these: the first two walked back previous British commitments, and the third potentially allowed states outside the euro to control the behaviour of states using the euro. So the other states went ahead without Cameron, joined in sulking outside by Orbán with Nečas and Tusk making up their minds.
I do wonder if Cameron deliberately set an unrealistic negotiating position in the certain knowledge that he would therefore return home with no treaty to sign, and thus avoid the embarrassment of either debating whether or not to have a referendum on the new treaty (or indeed holding the referendum and losing it). British journalists will no doubt concentrate on regurgitating the spin both from Cameron and the eurosceptics, but they are all marginal to the real process now. It is not so much a two-speed Europe as a one-speed Europe with stragglers, Britain being the largest of the later category.
Meanwhile, almost ten thousand kilometres away, the EU, the Alliance of Small Island States, and the Least Developed Countries are pushing in Durban for a new climate deal to include continuation of the Kyoto Protocol, more money to deal with climate change, and an agreed mandate to negotiate very quickly a new legally-binding agreement on carbon emissions by all the big players. They have another day to negotiate. This is where the action really is, in a sense; the euro crisis is only about money, while the Durban talks are about saving the world.