The Philosopher's Annual for 2011 (volume 31) can be found here. I've been looking back over the contents of past volumes (1-29; not sure where volume 30 went but there's a list on Brian Leiter's site here) and there is not very much in there about ancient philosophy. In the new issue there is “The Concept of Unified Agency in Nietzsche, Plato, and Schiller” by Paul Katsafanas in Journal of the History of Philosophy 49. Before then, Jessica Moss' "Akrasia and perceptual illusion" from AGP was in volume 29 and Michael N. Forster's "Socrates' Profession of Ignorance" from Oxford Studies in Ancient Philosophy in volume 27. Then (if I haven't missed something) you have to go all the way back to volume 12 for the next one: Jean Roberts' 'Political Animals in the Nicomachean Ethics' from Phronesis.
Well, perhaps ancient philosophy is a relatively small sub-discipline. But just 4 out of the 300 or so papers in the 30 volumes so far? True, things have looked better more recently. But I don't suppose that is because scholarship in ancient philosophy has got better only recently or that it has got better relative to scholarship in other areas of philosophy more recently. (There's a brief explanation of the process that generates the annual list here.)
Anyway, perhaps there's not quite enough published in ancient philosophy each year to put together a crop of ten papers for an Ancient Philosopher's Annual, but if we widen the search to include chapters in books, I think we could come up a few nominations. Any suggestions for 2011? Or even for 2012 so far?