Probably not, actually. South Korea has developed so far past the north that a full intensity conflict over this would be more of a loss for them than just taking a few casualties and sighing at the inanity of it all. Not that South Korea wants it to happen or is happy about it, but when the other option is breaking down the advanced society that you spent the last 20, 25 years building, the death of a few South Korean citizens (especially in the context of the Korean War never really ending) is the cost that is paid.
The little elite that runs North Korea and the military probably also know that a war would also not go in their favor, but because their society and economy is mostly a basket case, they have to do little things like this to try and press for concessions or economic assistance.
For now, it's probably the only reasonable situation both sides have - the humanitarian, military, and economic costs would be too great, otherwise. Of course, once Kim Jong-il is gone and Kim Jong-nam takes over, all bets are probably off. Sure hope that dude has some tricks and connections up his sleeve, because I can see him being eaten alive.