The first mention of the Q Continuum on the show as it was stated that there's been no contact with the Q in six centuries.
This episode introduces the USS Janeway and the NSS T'Pau, named after Captain Kathryn Janeway of the USS Voyager from Star Trek: Voyager (1995) and the influential Vulcan T'Pau that appeared both in Star Trek (1966) and Star Trek: Enterprise (2001).
First appearance of the Akaali since Civilization (2001). When the Earth ship Enterprise first discovered the Akaali in 2151 they were a pre-warp civilization in a pre-industrial stage of technological development (roughly equivalent to Earth around the 15th century).
First episode where Mary Wiseman (Sylvia Tilly) is not credited.