Personally i think that it is a good idea to spread the word of the new Sc2 Forum as much as possible, as it is a big and growing part of THW.
I do though think it's being done in the wrong way.
The Wc3 forums should have the Wc3 theme, and the Sc2 forums should have the Sc2 theme.
It should be up to the users to change that, if they want to.
It is, no offence, slightly silly to use a theme change to make people aware of the new forums when we have this big and flashy Notice Board at the top of the site that we are currently using to announce contests.
Put up some notices there every one in a while and people will surely notice the Sc2 forums if they have not already.
Maybe make them in another text color so that they differ from the contest announcements.
And if the theme change is in fact not an attempt to direct people's attention to the Sc2 forums, then i once again have to say 'no offence' as i think that changing THW's theme without any major reason is also slightly silly.
A public poll or maybe some warnings would at least have been nice.
Also i greatly disagree with this post:
Starcraft II must have a remote community website and not the hive. THW is becoming unruly since it supports two popular games. Users of THW now don't know what category do they belong.
I wont go in-depth on this one, but personally i'm happy that the hive offers both Wc3 and Sc2 forums.