Yes, North Korea has allowed tour groups for a few years now.
Supposedly its really, really beautiful in some parts, and if you are going to see the sights, and not the malnutritioned families that dont have any power, then it has the potential to be a wonderful sightseeing trip.
Its not a cheap holiday considering its citizens live a life worse than some third world countries, and for some reason they have very upmarket hotels and other forms of accomodation.
For a person living in South Korea (but obviously not south korean), we have to fly into North Korea via Beijing. You get your passports taken off you, and they dont stamp it either, then when you leave, you get it back, with no record of actually having been there.
Taking photos freely is a big no-no, talking to anyone is also forbidden, and everywhere you go, you have to have a translator.
They often make foreigners pay in US dollars, at exorbitant prices, so it would need to be a well planned, and carefully saved for holiday.
I have wanted to go to North Korea for a while now, but have never had the funds to do so. I think I would prefer to go there as a relief/aid worker of some kind.
So I dont really know all the ins and outs, but have done a bit of research.