As an Englishman living in Scotland (for fifteen years), I'm going to have my tuppence-worth.
It's a myth that English taxpayers pay for Scotland. Utter tosh, in fact. Leaving aside the tax take up here (the average person living in Scotland pays more tax than the average person living in south-east England (excluding London), for a start), as someone else pointed out, government money is collected and then distributed around the country (ie the UK) - there are some things Scots pay equally for, but don't get a fair share of, just as there are some things Londoners, for instance, pay for but don't get a fair share of. That's just the way it goes. In an independent Scotland, Edinburgh and Aberdeen would shell out considerably more than they receive; the islands would receive considerably more than they pay out. It's what the state, and the government, does. If you don't like it, start campaigning for the abolition of state and government.
The myth, ironically, was created in order to try and counter pro-independence feeling, but has actually done the opposite. Of course, a Scot who wants inpendence doesn't give a monkeys about the financial issue - nationalism is about identity and emotion. Just as those who want to retain the union don't give a toss whether or not they will be better off or worse off in the UK, supporters of independence would be happy either way. What the myth has done is create support for Scottish independence in England.
Recent support for the SNP has been based on a (partly eroneous) belief that they are a social democratic party. Scots are, in the main, social democrats, and the SNP is clearly more social democratic than Labour, the Tories and the LibDems. However, Brown is starting to speak like (if not act like) a social democrat, and the bounce, in Scotland, is far from negligible. I doubt it will have the same effect in England, but we'll see.
There is of course, something else to be considered when looking at Glasgow East and Labour. In Glasgow East, the SNP was already very popular, and the unquestioned opposition to Labour; the Tories and the LibDems were nowhere. In Glenrothes, the LibDems and (to a lesser extent) the Tories had a fair bit of support. The mathematical swing looks like a small swing Labour to SNP; actually, it's a very large swing of LibDem and Tory voters, knowing that their parties had no chance, swinging to Labour. Leaving aside the very real reasons for calling the SNP the 'Tartan Tories' (a popular phrase up here), LibDem and Tory voters in the east of Scotland know which of Labour and SNP suits them most and is closest to their own beliefs (and not just on the union).
On support for the union/independence: many SNP voters don't support independence; many Labour, LibDem and yes, even Tories, do. Don't take support for the parties to reflect support for independence and union. Nevertheless, most Scots do not support full independence, although the very large majority of Scots do support devolution, and very many of them would like to see it extended, with more powers transferred to Holyrood.
Whenever I hear people in England complaining about something the Scots have that they don't (eg the student funding settlement, free bus travel, free care for the elderly and so on), my simple answer is this: it's what Scots want, it's what they have campaigned for, it's what they have voted for. If England, or the rest of the UK, wants the same things, then start campaigning for it and start voting for the parties who would offer it.
I could go on, but I suspect I'm already boring everyone.
