Portal/Half-Life 2 Clarification

Planet Half-Life has a story up clarifying that Portal in Half-Life 2: Episode Two is a separate game from Half-Life 2 that does not exist within the Half-Life continuity (thanks Ant). This strikes us as how the project was described from the get-go, but in case there was any confusion, they distill a couple of recent interviews to clarify the situation:
With Portal co-existing in a world along with Half-Life, crossovers are a definite possibility. Unfortunately, according to Kim Swift, we won't be seeing any Portal gun versus Gravity gun duels in the foreseeable future. Rumors surrounding the device's name, "Aperture Science Handheld Portal Device" suggested the return of another Half-Life character, Adrian Shephard. Adrian, the central character to Opposing Force, meets a similar fate to Gordon Freeman under the G-Man. Though the sequel to Half-Life continues Gordon's story, the whereabouts and condition of Adrian is still relatively unknown.