I'be been looking at the muse as well. I know there is a large and an oversized one but I'm not sure about other sizes.
I think some of these celebs really need to rethink carrying around the oversized muse, like Jennifer Aniston as it looks likes she's struggling with it.
There is a tiny Muse for evening wear but basically for day time there are the medium, large and oversize. I have the large and I think it is the perfect size because it (hopefully) won't look outdated when giant bags go out of style but yet it is still quite large but not overwhelming and I'm only 5'1".
When I got it the SA at the YSL boutique in NYC said that the bag was meant to be large and that the medium size would not give the same effect. She highly recommended that I go with at least the large size and I'm so glad I did.
Every time I see a chocolate Muse in large on the N-M site it is gone within a couple days. I hardly ever see the large size... mainly the oversize. The YSL boutiques seemed to have them when I was looking earlier in the fall.
The bag that Nicole is holding in this picture (from one of the posts earlier in this thread) is not the Muse. It is the Yse bag, which is very similar to the Muse. Here's a link to it at N-M but not in that color. I had seen that color on the N-M in the past, though. This one from N-M is bronze with chocolate suede trim and is on sale from $1595 to $1117!