Yep, in '08 they made the Library into a "package". It's very annoying!If you want to browse your Library in the Finder, right-click (or control-click) on the iPhoto Library and select, "Show Package Contents".
Every person who has ever done support for iPhoto stood up and cheered when they turned the library into a package! People who didn't know better broke their libraries left and right by going into that folder and moving stuff.If you want to access something from iPhoto, just drag it from the iPhoto window to the desktop, and you'll have a copy of it to play with.
I noticed this as well. It's craptacular.