First comes the fear of goldfarming influence. When the news first broke, there was talk of Affinity's relation to goldfarming company IGE. All ties have purportedly been cut by Affinity, clinching the deal for Wowhead. To be sure, no goldfarming or power-leveling ads have been shown on the database site. Affinity CEO Mark Jaffei claimed in a Q&A that the original leaker of the acquisition talked up goldfarming has financial interest in a competitive site.
More importantly comes the fear of non-competition, as the three biggest WoW databases -- Wowhead, Thottbot and Allakhazam -- are now all owned by the same company. The battle for traffic hits had pushed the sites to improve the quality of their databases, and there is worry that Affinity will not require competition the three sites. Only time will tell if those fears prove valid. Check out WoW Insider for a thorough analysis of the news.