I presume you meant Nordea for opening the account. They are well rated, and if their share price is anything to go by, they have weathered the last 3 years of financial crisis relatively well. The SEK is a stable enough currency and not as commodity influenced as e.g. the NOK. I don't think its pegged to the EUR (ERM) like DKK. The big question is, if the EUR went pear-shaped would a relatively small economy like Sweden not be pulled down by the fall-out. Maybe not. but you are proably right to diversify cash across currencies at this stage, as well as domicile - obviously there would be CGT issues on any gains on the re-conversion to Euro.
At a local level, NIB offers SEK accounts, as well as DKK, and NOK.