well... in comparison to the time between HL and HL2, the delay between the episodes is much less.
from HL1 to HL2 was a SIX YEAR delay, and from HL2 to EP1 only 2 years, and only another year and a half from EP1 to EP2
HL1 - 20-25 hours of gameplay
6 years pass.
HL2 - 15-20 hours of gameplay.
We are told sequels in episodic format would bring "More shorter games more often".
2 Years pass.
Episode 1 - 5-6 Hours of gameplay
1.5 Years pass.
Episode 2 - 5-6 Hours of gameplay.
2.5 Years pass
Nothing, no news, release estimate 2011.
So in the 6 years between HL and HL2, they made a game that had 20 hours of game play in it.
In the past 6 years since HL2 came out, they have made 2 games containing in total about half that, with no more estimated for more for over a year, so in 7 years they have provided 10 hours of gameplay.
Honestly I think that is rather pathetic, HL is their most successful and popular franchise, has MASSIVE fan base and yet they have practically ignored it. I think I have every right to be a bit miffed with them.