Portal/Half-Life 2 Clarification

On Planet Half-Life is a story clarifying that Portal is a separate game from Half-Life 2 and does not exist in the Half-Life 2 continuity. It was initially built to be added to Half-Life 2, though they later decided that it would be too distracting. They extracted this information from a couple of 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.

It would be interesting to see if Portal continues the story of Adrian, though it seems unlikely.