no not even hl2 will support ingame terrain forming...
as we allready so on the game red faction, which had complete destructible terrain, the multiplayer experience was kinda thumb cinema (lag lag lag). ppl would have bought the game for the singleplayer campaign, but why did they implent complete destructible terrain when it isnt even needed to achieve the goal of the singleplayer campaign?
so they invested so much money into the engine, which didnt fullfill either of the jobs: singleplayer and multiplayer
it will still last for many years until we will see a game with destructible terrain, which has no lagging multiplayer experience, and which supports big exterior environment (which esf does need)