The future of Scotland is actually fascinating right now. A terrific piece of analysis can be found here by Jackie Ashley. One looming alternative to complete independence is the Scottish Nationalist Party's proposal of "devo-max" which would ask Scottish voters to approve everything-but-independence from Britain:
It basically means the Edinburgh parliament and government getting control over everything except defense, foreign policy and macroeconomics. It would keep the pound, the British army and the Queen.
This may be particularly interesting if the next government is a Tory one dedicated to tough spending cuts (the kind the US Republicans are too dishonest to propose). Scotland gets a disproportionate amount of public spending - it's a red state in an American sense. Real cuts would therefore further inflame Scottish independence, even though David Cameron is a staunch unionist. But he is also a Tory.
And if Scotland's seats were removed from the Westminster parliament, the Conservative Party's structural advantage in England could tip the political balance decisively to the center-right.
For my part, I increasingly find the union with Scotland an anachronism. Britain is a largely false construct of relatively recent origins, forged on empire and now without much of a purpose. For England to shrug off the fiscal burden of Scotland and Northern Ireland would be a huge gain for the over-taxed English. And Saint Andrew wouldn't be too miffed either.
(Painting: The Calling of Saints Peter and Andrew - Caravaggio.)