Did you all know that this is what wikia sends to people who ask for SMW?! I'm glad I've gone with Referata.
Thanks for contacting Wikia. Semantic MediaWiki is a very powerful extension. It can let you do some great things on a wiki, but that power comes at a cost. Queries can make wikis slow, which can be frustrating for visitors. Often, there are less costly extensions or built-in methods to achieve the same effects. So please consider your request for Semantic MediaWiki further. A comprehensive guide can be found at http://semantic-mediawiki.org
Even if you do know you need Semantic MediaWiki for a specific task, we still strongly urge you to take a minute to read the guide.
If you want to go ahead with this feature, please let us know. Or, let us know what you want to achieve, and we will look to see if there is a better way than Semantic MediaWiki.
Wikia Community Support Team