Actually, clothing and shoes have offered multi-variation listings for quite some time, as they were one of the biggest areas in terms of multiple-choice (size, colour, etc.).
Here is the result of a search which indicates that category does offer multi-variation listings:
http://pages.ebay.com/sellerinformation/sellingresources/multiplevariationslist.html
To the OP: One point to keep in mind is that even though these listings allow buyers to choose a particular size, colour, etc. from the drop-down list at the top, keep in mind that many buyers aren't aware of this, or aren't sure what to do.
I would strongly suggest that if you use multi-variation listings, you also put a complete size chart in the description portion of each applicable listing, showing all the sizes available for that item, and directing buyers to choose the size they would like from the drop-down box at the top of the listing. You'd be surprised at how much difference this little bit of information will make.
Best of luck!