Source needs an upgrade. If it honestly isn't Source 2, then they have gotten everyone's hopes up and are going in the wrong direction. There is no point in continue releasing games in an industry who's engines are drastically changing at a rapid rate.
Source is outdated, its as simple as that. L4D2 has so many flaws due to limitations of the Source engine, and with this new engine they have so many more engines, assuming its true. HL3, CS2, L4D3, Portal 2, TF3 (This would be out of control), and even whole new franchises like Sci-fi games and a new type of RTS or RPG.
Source 2 would be the best way for this company to move forward and they will be losing a lot of opportunities if they don't announce the Source 2 engine or at least start working on one.