While I am not necessarily interested in these glosses per se, I am also not surprised that MAC keeps cranking out the new formulas. A lot of brands have been creating new formulas, and they have all been selling well. Lipgloss is also pretty universal. More age groups and individuals will reach for gloss before eyeshadow I think.
I really hope they combine the sparkle of dazzleglass with the creamy pearl of creamsheen glass. That would be good!