New states and separatism have been somewhat of a taboo subject in Europe, and for good reason. Just check out the
list of active separatist movements in Europe.
Now, most of those probably are not politically noteworthy, but still, if Scotland manages to put the idea of secession back on the list of acceptable topics, things could get interesting. (Some have argued that one reason why Europeans states are generally not in support of Kurdistan is because they just really, really don't want to start talking about borders drawn in the imperialist era that don't follow ethnic lines...)
The most interesting situations to follow would be I think Spain (Catalonia and Basque Country) and Italy (Northern Italy, Venice and South Tyrol (which wants to join Austria)).
One interesting thing here is also that pro-independence parties tend to lean a good distance either to right or left of the what ever the local political center is. If the independence movements start to get traction, they could alter political landscapes significantly. (Which many think is ripe for change anyway.)
In that light, it's not hard to predict that most current governments in Europe will not show any sympathy to the Scottish independence movement. Joining the European trade unions or EU for example could turn out to be "surprisingly" difficult.