O'Reilly has a couple of other new Perl books in the works for July or August release. They aren't revisions or second editions. I don't know about Apress.

I know the relative marketshare of both publishers, but I'm not sure I should share. Tim O'Reilly has talked about it several times in the past two years, so look at his weblog or search for discussions of his "State of Computer Book Publishing" talk.