Yes its out m8, It would probably be cheaper to get it through steam, Its £19.99 in the shops over here, But only $19.99 on steam I think that is somewhere around £12.00 though it maybe on offer somewhere else cheaper, I know its £14.99 on Play.com.
Here is a link to the Official website m8 if you want to see the video ect, Like I say I didnt see much different in it thats why I didnt bother. But If thats a video of Eps2 you posted that is a step forward from Eps1.
http://ep1.half-life2.com/