I've just received a copy of a volume containing a few interesting papers that deal with skepticism: Quentin Smith (ed.), Epistemology: New Essays (OUP, 2008). Among the contributions bearing on skepticism the following two are to be mentioned:
"Skepticism and Perceptual Knowledge" by Ernest Sosa.
"Knowledge-Closure and Skepticism" by Marian David and Ted A. Warfield.
For complete information about this book, go here.