The United Nations released today the new United Nations Treaty Collection Database, including the full-text of agreements in the UN Treaty Series. For those that miss the old interface, it does include a link to the legacy site. It does include a new search interface. Many thanks to the folks at the UN Treaty Section of the Office of Legal Affiars for their work on the new database.
New United Nations Treaty Collection http://treaties.un.org/
Old legacy site: http://untreaty.un.org/