Venture Beat reports that iTunes has been blocking submissions to both the App Store and Mac App Store when a developer tries to upload an app that has the word "free" in its name. Though Apple has previously discouraged this in the past, it is now showing this message to developers who try to submit "free" apps:
Your app’s name, icons, screenshots, or previews to be displayed on the App Store include references to your app’s price, which is not considered a part of these metadata items.
Please remove any references to your app’s price from your app’s name, including any references to your app being free or discounted. If you would like to advertise changes to your app’s price, it would be appropriate to include this information in the app description. Changes to your app’s price can be made in the Pricing and Availability section of iTunes Connect.
According to The Verge, Apple has confirmed this new policy. However, it's not totally clear whether developers will be forced to change the name of existing apps if the price is currently mentioned in their title — though any updates to those apps may be rejected in the future.