"Following the nomination by British Prime Minister David Cameron of Sir Julian King as the candidate to replace outgoing Commissioner Lord Hill, President Jean-Claude Juncker will receive him on Monday, 11 July at 11:00 (CET) for an interview." (COM press release, 8 July 2016)The announcement that the UK's ambassador to France (since this year), Julian King (Twitter), would be nominated as candidate for European Commissioner for the UK has been floating around for days, so nothing surprising in the Commission's press release.
What will become interesting is (a) whether Juncker will propose him as a candidate after the interview on Monday, and (b) whether the European Parliament will actually endorse him as Commissioner and (c) whether, in case the EP refuses him, the Council and the Commission President would dare to go against the will of the parliament.
The press release specifies these procedural aspects:
"the appointment of a new Commissioner of UK nationality requires common accord between the President of the Commission and the Council after the consultation of the European Parliament … . In addition, the Interinstitutional Framework Agreement on relations between the European Parliament and the European Commission requires the President of the Commission to “seriously consider” the results of the consultation of the European Parliament – which will audition the candidate – before giving his accord to the decision of the Council to appoint the new Commissioner"King's CV shows that he had not only experience as representative of his government at the EU Council of Ministers (1998-2003, 2004-08), including as representative to the EU Council Security Committee during the time of the UK's last presidency of the EU Council (as proven by this document). Afterwards (2008-09), he was also in the cabinet of former UK EU Commissioner Catherine Ashton while she was still responsible for trade, not foreign affairs.
Thus, he knows his way around the Council, including at the level of the Council Presidency, and he has served at cabinet-level inside the Commission in a not-so-distant past, which will have given him quite some insights into Commission business.
In other words, the UK sends a person who looks very much qualified for the job, probably better qualified in EU terms than any of his recent predecessors. Don't know anything about him personally, but, short of Jonathan Faull, this sounds like a good choice and I don't see why the EP should not approve him except for broader political considerations.