Some of you may have seen the post on P'ssion's blog showing an upcoming collection from OPI called Femme De Cirque, which will be an addition to their SoftShades colors. Sally Hansen's Hidden Treasure seems to have popularized these milky shades with iridescent glitter, because Barielle has a similar shade in their upcoming Spring collection (left), and OPI's I Juggle...Men (right) from Femme De Cirque seems to have a somewhat common theme.
I personally love these types of shades as layering top coats, and while they may have the same basic concept, they do have some rather obvious differences. Hidden Treasure has the large flakies like Barielle's new shade (or so it seems by the bottle photos), but they're more of a pinkish/gold color, while Barielle's looks to be more green. I Juggle...Men has smaller, more defined glitter that is a blue/lavender tone and reminds me in theory of Orly's Love One Another, although that base color is more lavender.
Who knows how similar any of them are to other polishes at this point, but I for one will be looking forward to both of these new shades!