It's definite in that a story appeared in the Times on 25th November:
Since I can't seem to get the URL, the key snippets are:
"IN THE finest tradition of the Royal Navy, the two large aircraft carriers that are to replace today’s three smaller warships from 2012 are to be named HMS Queen Elizabeth and HMS Prince of Wales.
After months of detailed study by a special committee that examined a long list of suggested names, including a number of instantly rejected ideas — such as HMS Millennium Falcon, HMS Death Star and HMS Galaxy Blaster — the Queen is understood to have given her approval for her own name and that of her son and the heir to the throne to grace the hulls of what will be the biggest warships built in this country. ...
...The carriers will be called the Queen Elizabeth class, and the first warship will be HMS Queen Elizabeth.
The recommendation to give the first carrier the name of the Commander-in-Chief and the second the heir to the throne was made by the Ships’ Names and Badges Committee, which is chaired by Captain Christopher Page, head of the Naval Historical Branch.
The committee’s choice was first passed to Rear-Admiral Nigel Guild, Controller of the Navy, who then sought approval from Admiral Sir Alan West, First Sea Lord and Chief of Naval Staff, and finally to Geoff Hoon, the Defence Secretary. Mr Hoon passed the Ministry of Defence’s choice to Buckingham Palace for the Queen’s approval.
The Ships’ Names and Badges Committee considered social trends — and political correctness — as well as more weighty issues such as previous ships of the same name and historical background.
The committee members, who include the naval adviser on heraldry, automatically ruled out a number of previously famous wartime names because of their modern-day connotations — notably the Gay class and Flower class warships.
A defence source said: “The Flower class corvettes of the Second World War (such as HMS Pansy, HMS Meadowsweet, HMS Wallflower, and HMS Periwinkle) were fantastic ships but I think today’s Jack Tar would be less comfortable with a cap badge with the name of a flower on it.”
Among the considerations examined by the committee when it had produced a shortlist were: does the name have a strong Royal Navy tradition; does it have many battle honours; is there a sufficient gap between the paying off or demise of the previous ship of the same name; or is there an unhappy history? A past record of wartime tragedy, however, was definitely not one of the reasons for including a name on the rejected list. "
As far as I can see, though, the Times is the only paper to have run with this, and there's nothing on the MoD website.