First of all thanks for the update, the blending is very nice =D
I've noticed something weird about markers.
When using a dry marker (0% wetness) and a light color, above 50% luminance, I notice a different behaviour than when using a darker colour. With a dark colour, the first stroke with a dry marker is lighter, and the next strokes build up uniformly to the color I've selected. When the colour is lighter than 50% though, the marker has an entirely different feel, that looks like chalk, or as if it hasn't got enough ink, on the first stroke, and additional overlapping strokes build up to a color with the same hue and saturation values as the selected one, but with exactly 50% luminance. As a result, trying to cover uniformly a surface with ,say, a pale red, will result in chalky lines which overlap to a rich saturated red. The effect goes away at 100% luminance , which is pure white, and which remains white.
Doing the same with the wetness set to 100% will give a color closer to the selected one, much darker still, and with wet streaks all over...
What strikes me as odd is the different behaviour above and below 50% luminance.
I can't post an image right now, but I'll try to do so soon. To see what I mean , though, just scribble a bit with a dry marker, and a color of whatever hue (though red shows the effect best), 100% saturation and 70-80% luminance, and then with the luminance to 20-30% to see the difference.
Perhaps it's intended, but then why the different behaviour? why not have them all build up to black or a dirty gray as real markers would ? (though I certainly would prefer it the other way around :P)
PS:Oh and about those streaks when the marker is set to a high value of wetness. Would it be possible to tone the effect down a bit? It surely gives a 'real' feel to the markers, but as it is, they are the only glazing tool available (which can give very nice results over other media) and though wet markers blend very nice, the streaks are somewhat in the way :P