Don't think it's going to happen, yes the SNP might have won the 2011 Scottish PArliament election. But lets examine the figures
SNP (pro-independance) 44%
Other parties (anti-independance) 56%
So assuming an independance vote was held, and everyone voted along party lines it wouldn't pass. Of course it's not that simple because just because you vote for a party doesn't mean you support all of it's policies.
As far as I know, Scottish independence is also adovcated by the Scottish Green Party and a couple of a smaller left-wing parties whose total vote share (added to the SNP's) would amount to 49% and not 44%.