from what I have been seeing on the HLDS Linux mailing list...Yes! There will be a dedicated server for L4D2, but the current discussion is about how many forks will it be able to handle since Valve updated the AI, and the engine on L4D2. Talks have been that people with 8 to 10 forks will now be reduced to half of that because of the changes between L4D and L4D2.
If you are looking to get a demo server started, I would hold off for the next couple of days until Valve gets things sorted out. From what I can see on the mailing list is that there are some permissions issues with the .so file bins for the linux distro. Not sure exactly what is going on with the Windows servers, but I am quite surprised to see Linux bins released early.