Perhaps the camelbook authors aught to write another edition? I know I'd buy it again just to have it on the shelf. I'd probably even read it again, since (as I recall) it's written quite well.
I'd buy one. I never did upgrade my copy of 2nd Ed. By the time I had abandoned the notion that Perl 6 was coming out in the next decade, the language had moved a few versions past the 3rd Ed. Camel Book, and who wants to buy a book that's already comparably obsolete to the one they already own?