I think most Scots never thought they would see the day when an SNP administration held power in a Scottish Parliament; even less would have expected to see the possibility of an independence referendum in their lifetimes. On the other hand, getting the referendum actually to take place seems unlikely for the time being; the minority administration seems unlikely to be able to get the required number of votes. (For shame! I'm looking at you, Liberal Democrats!)
Perhaps that is for the best, for the Nats anyway: there has been very little change in support for independence in recent years, with the rump of around 30-odd % remaining fairly static. They are pretty much obliged to petition for a referendum at the earliest opportunity (as they have done), but at the moment it seems unlikely they would get their preferred result.
I should think, if and when this referendum is shot down, the SNP will play the long game (well, they have been playing that game for quite some time now...): Let's assume Westminster returns a Tory government (although more polls are pointing towards the dream scenario for political anoraks - a hung parliament!) but without a Scottish mandate (I'd expect them to improve on their sole Scottish MP, but not by much). That's mana from heaven for the SNP (1980s all over again, anyone?) We might reasonably expect the subsequent Scottish Parliament elections to return less Labour MSPs (as a result of their slump, post-defeat; and, if the further left can stop the factionalisation and split the Labour vote) and, perhaps, less Lib Dems (as they are a declining force in Scottish politics) - leading to more SNP MSPs, if not a majority (which is extremely unlikely for any party under the current arrangements).
In a sense, then, I'm surprised the Unionist parties won't allow a referendum now: they should be confident they could win it, and that would - as the SNP accept - mean no further independence referendum in 'this generation'. Leaving it for the time being - and, I should think, delaying what will be at some point an inevitability - surely carries more risk.