I have seen many people on forums and on IRC say they would rather see CZ on a new engine.
Im not saying thats a bad thing at all however in my opinion it would be harder than hell to get the game to have that same feel of Counter strike on a new engine.
What would the odds be for any developer to recreate what some may consider to be one of the largest spoofs of known FPS history in a new engine? Believe me if I knew this secret I would start my own company and get cracking right away.
Also id like to point out that even though this engine is pretty old you can still do some really cool and fun game play. All of the level designers on this project came from more modern engines and I feel it hasnt really harmed the visual quality we expect from ourselves that much. hehe