The website held an interview with Doug Lombardi who is responsible of everything PR related inside Valve Corporation.

Lombardi explained in the interview how Portal's engine allows the mechanics to create portal from one point to second. Interview continued to Half-Life's future when asked first the estimated release date of Half-Life: Episode Three and then if there are any plans for Half-Life 3.

"We haven’t announced anything specific, but Half-Life won’t end at Episode Three – hang on to your crowbars!", answers Doug Lombardi.

This gives a clear picture of Half-Life's future as Valve will most likely exploit the Portal engine to Half-Life's future versions, but from now on we have to wait for more official details. Stay tuned!