Jim, I don't see it as a case of recruiting aged pop stars now, it's more a case of what they were doing in their heyday. Thin Lizzy's hit with Whiskey in the Jar in the 70's may have would have undoubtedly introduced many pop/rock listeners to a traditional song and may have sparked an interest to dig deeper. Similarly with the other examples quoted. This is likely to keep happening in the future with current pop bands/artists.

I agree with Deepdoc that it's in the past it's probably not been the main way of attracting folk to folk, and it probably won't be in the future, but it does have an effect nonetheless.

I can't say it's worked too well for me with English folk, but it's certainly been the case with blues - i.e. tracing the line back from Clapton through Robert Johnson through to his influences and beyond.

Pete.