Errr... no. It's "Consolidate Library..." in the singular, which takes any files that are in your iTunes list, but are stored outside the iTunes folder, and moves them into that folder. It does not consolidate multiple libraries.
I don't know of any way to consolidate several libraries and maintain the sum of the play counts, etc. But if you just care about the media, then take the other folders and just drag them into iTunes to add the content, and then use a duplicate-removal script to nix duplicates.