Pretty neat, it's not just a mod, this modder has been improving the HL1 engine with modern features and effects and better physics, and then added a mod on top of it. I've been following it for years, not closely though.

Here's the 2011 trailer:
http://www.youtube.com/watch?v=2OsSlzML7YQ

It will be released next year probably, and you can vote for it in the MOTY 2011:
http://www.moddb.com/events/2011-mod-of-the-year-awards

then here, http://www.moddb.com/mods/half-life-1-arrangement

Bonus trailer: http://www.youtube.com/watch?v=gtx-KNVjf8M ;)

That's looking really good for a mod of a 13-year old game. Movement seems immersive, judging by the trailer, but it might as well be annoying, it's hard to decide before playing.

For now, I wait.

Yep the strafing to left and right can be a bit annoying, but personally it didn't affected me much, it adds a sense of action that the original half-life doesn't have.

Here a trailer years old featuring Half-Life assets and monsters for a comparison; The final mod won't use HL assets:
http://www.youtube.com/watch?v=dgmcAIMHKYs