If they want to go then they can go. I used to want the UK to sty together but after living with a Scottish house mate who regularly says awful things about English people and insults me constantly due to me being English I really don't care any more. I know it's a bit sad that one utter bastard is colouring my view quite badly but that's how it is at the moment. At least he shut up for a while when I asked him why the hell he was in England if he hates everything about the country.
OK rant over now.
On a more practical level I think all of us would be better if the UK stays united but in the long run I think Scotland would end up far worse off than England if they split. I'm not sure what would happen with the Oil etc, I'm sure there are people behind the scenes trying to figure that out!