Maybe not for large-scale web applications, but as webserver for a small blog or as a proxy server, or even just an Icecast Server for some friends, why not?
The GPU would be mostly idle in these cases, as Servers don't usually run a Graphical Interface, which would mean more RAM for the system.
All in all, this might well be an Application the RPI is more suited for than functioning as a media center.
Version of the link in English.