User blog comment:Brandon Rhea/SWFanon is beta testing the VisualEditor feature/@comment-973828-20131022175048/@comment-5275700-20131022204634

There's no spell check built into the feature itself, it simply utilizes your browser's native spell check functions. So you should see the same behavior you see when editing source (in that browser), and doing other text entry on the web. If you're not seeing that, please provide a few examples.