I was getting the same error; I had previously installed the google-play-services_lib for Google Maps (and it was working fine) but then when I later tried adding the meta-data entry to my Manifest I was getting the error. I tried all the above suggestions but nothing would link them properly; I finally removed the link from my project (project-properties-Android, remove google-play-services_lib library), then removed from Eclipse workspace, deleted the files on the disk, and finally used the SDK manager to reinstall from scratch.
That seemed to finally do the trick; now Eclipse has decided to allow me to leave the meta-data entry with no errors.