WON-based CS will die on all but privately owned servers, because CS-Source is growing in popularity, not to mention that WON-CS is not being developed/supported anymore. Just about everything else has dropped off.
STEAM was inevitable. It was buggy in the beginning, and it is meant for broadband connections. The number of people with broadband is going up, not to mention the amount of server-client traffic is also going up. Let's not even get into the whole mess of updating beforehand. Now I don't have to go tromp through sites finding a fast and available download for an update, STEAM does it automatically for me.
Once you learn how to work it and tweak it, it's great.