I think this is an interesting interlude for the Norwegian CP couple and family. It is only for 2 months, so couldn't really be considered as 'bringing up their children in a foreign country' - which most countries are against happening with heirs to the throne.
Although SM is quite young, M is getting to the stage in his education where disruption is not a good idea. Also, the King is not getting any younger and, although he made a good recovery from his recent ill health, it may only be a few years before Haakon has to take over most or all of his work-load as a Regent.
Also, they have said that they are paying for the trip with their private money. Security would have to be provided anyway so it will not be a big extra to have some travel with them.
As to the British Royal Family - you will hear a lot of negative comment from the media generally, and there are some very outspoken anti-monarchists (and many students - who always like to protest againt the status quo!). However, there is a very large 'silent majority', which is happy with and proud of our traditions and way of life, including the Monarchy. If you think back a few years, the BBC let it be known that it wouldn't be doing much coverage when the Queen Mother died. Then, when they saw the great outpouring of respect from the ordinary majority and the way they lined some 20 miles of road, spontaneously, when her coffin was moved from Windsor to London (or was it the other way round?) they changed their mind. The media is often out of step with people, and can believe their own propaganda too much.
