Maybe an unpopular opinion, but why change the current arrangement? It seems to work very well for all participants. Norway is already an EU member in all but name when it comes to applying the EU based regulatory standards. There's also freedom of movement. Meanwhile Norway can keep its independence in a few key areas that are of importance to it, including fisheries and an independent currency. Unlike the UK or Switzerland this is a solid basis for long term cooperation between trusted neighbours. If Norway decides to join they should be welcome. But until then the current arrangement is perfectly fine already in my opinion.
Theres talk of adopting the euro regardless of membership status whether that is just binding our curremcy like the danes or actually changing. Our currency is a joke and with the euro gaining momentum as a safe haven currency we will be left even further behind with our oil based currency. We lose sovreign control of interest rates and money supply though and im not too sure how well that worked for eg greece....
No, I think that having more standardisation is key. Just join as a full EU member, and everything will be easier. Why bothering having your own currency when we can all have the euro?