The edinburgh population has a large percentage of celts and anglo-saxons, however scotland is now a multi-racial country. Edinburgh has a pretty cosmopolitan feel to it, particularly during the summer. This is partly due to the influx of tourists and those working in hotels, restaurants and bars, but there are also a good many 'foreigners' (or non locals) living in edinburgh, attracted by employment opportunities and the general quality of life.
Like the city itself though, there is certainly a feeling of 'Scottishness' amongst the locals. They can be a little 'stand-offish', particularly when compared to the people of Glasgow (who come across as more helpful and friendly), but it's hard to generalise. They are certainly nowhere near as abrupt as the people of london.