It would be good to have a year round service, but it appears from purely my own experiences that the CO / AA / US services are aimed at the outbound Scottish tourist market, meaning that winter services would be impossible to maintain (with the exception of CO, of course, who have the market to themselves in winter). EK has a much bigger market, such as VFR traffic to Pakistan / India, the Far East and to a lesser extent Australia. DXB is a good connecting point as many people like the Duty Free option there.
I also know of people who use EK to South Africa from Scotland, so they do have worldwide market. Not sure about inbound traffic though, which is presumably what the Scottish Executive has in mind with its subsidies.
kpik03, think PIK needs some better First / Business Class facilities to attract more regular non low cost services, but other than that, it would be fantastic to build up more routes a la BWIA there.