These are not the only servers that are likely to be impacted. Servers for Homeworld, Darksiders, Red Faction and Nexuiz could be impacted, as these are titles that did not sell in the first THQ auction.
The developer of Nexuiz, Illfonic, says that they will keep the PC servers up and going, but this is because they control these servers and runs them itself. THQ was responsible for running the Xbox 360 servers, so there isn’t anything it can really do about it. While they could obtain control and shoulder the cost of the servers for the Xbox 360, it isn’t justified at the moment with no revenue coming in from the Xbox 360 version.
It is expected that Nexuiz will be taken down from the XBLA for purchase if it has not been removed already.