Valve has confirmed that it is currently working on introducing support for competitive matchmaking in Team Fortress 2, and that it views this as a very ‘high priority’ project.
According to TeamFortress.tv, Valve seems to be exploring multiple options- as of right now, they are looking at 6v6 matches, 9v9 matches, a quick play option to just jump in, and also, potentially, lobbies.
TeamFortress.tv declined to mention whether the matches will be Highlander based or Manpower based. It is possible that they themselves do not know at the present. Nonetheless, they have promised that they will be sharing all the information that they have on hand tomorrow during their podcast, so we should have some clarity soon, and should be able to update you.
For now, if you are interested in knowing all that there is to know about this competitive matchmaking, you can check out the video that TeamFortress.tv shared, where they basically tease their big reveals coming tomorrow.