I've literally just made the move back to film, having fallen in love with Tri-X and HP5 (especially when pushed to 2000 in Xtol), and from all the looking through galleries, looking online, buying prints and stuff I've done, I think the 'Leica glow' is a combination of the gorgeous bokeh produced by the Leica lenses and how that bokeh distributes light accross the film. Then the second step is obviously for the film to be developed right, and it's somehow in the grain as well.
I don't think that the Leica Glow will quite translate to the M8 because the M8 will produce noise where grain is needed and Noise isn't beautiful, whereas grain is gorgeous (well... Tri-X grain is, Kodak Gold grain is... I tried it out as an experiment.... I wanted to cry it was so ugly)
Scanning can reproduce the Leica glow, however the problem that there is no way to tell how other people's mointors are calibrated - so different mointors will retain or destroy that glow. Old style 'softer' monitors which aren't flat screens actually help reproduce the glow better. Also the black on it them are blacker and a nicer smoother contrast....
But I wouldn't rely on digital to reproduce the Leica glow - it happens pre-production, not in post production. The print can also be made to glow (or not if poorly printed) if it's 'right'. It's a balance between those two things that will give you 'the glow'.
I feel like a nerd now. I'd say 'I need a girlfriend' but somehow I have one. I'll scare her off soon enough.