Third Guild Wars Campaign Called Nightfall?

1Up is reporting that NCsoft has obtained a trademark for the Guild Wars: Nightfall title and has even snagged the guildwarsnightfall.com domain name:

From E3 we reported that the next Guild Wars game had some very early details emerge at the conference. Now, a trademark for Guild Wars: Nightfall has surfaced (you’ll have to enter “Guild Wars: Nightfall” in the link, the search engine resets in new windows). Additionally, a Whois look-up showed that NCSoft registered the URL www.guildwarsnightfall.com — is Nightfall the name of the next Guild Wars expansion? According to our magic 8-ball signs point to yes.

Why NCsoft, as opposed to ArenaNet? Does a publisher typically handle trademarks and official websites?