Thanks Roger - that's a 'sign'.... We'll likely be seeing more on this as ecigs get more press.
You're right on the 'dual use' issue, but Glantz is truly wrong. Without a 'survey' but from personal anecdotal evidence here and in life, "dual use" has been along the lines of "I went from a pack and a half to 6 a day" - I know of 6 individuals, locally, where this was the case - 4 have since gone all vaping and two still have a few cigs a day - usually that first ones in the morning.
I went from an average of 50 a day to just 6 in the first week and I was opposed to even trying an e cig. That lasted for 7 months. Now it's been over 4 years since my last drag.