The creators of the Pokemon trading card game are suing Nintendo of America and Pokemon USA.
According to a weekend article in the Seattle Post-Intelligencer, Wizards of the Coast has filed a suit against Nintendo of America, Pokemon USA, The Pokemon Company, and two executives. Wizards created the Pokemon trading card game and oversaw the product for years until Pokemon USA recently absorbed those operations. Wizards of the Coast produces several other card games, including Magic: The Gathering.
The lawsuit alleges that Pokemon USA and Nintendo undermined their relationship with Wizards of the Coast, apparently so that the once-lucrative Pokemon card business could be transferred and rebuilt under Nintendo's umbrella. The suit also makes accusations of patent infringement and mishandling of trade secrets.
At the heart of the matter are two executives who once worked at Wizards but eventually were hired by Pokemon USA. The lawsuit basically says that these people went to Nintendo and gave away various information that they were bound to keep secret by non-disclosure agreements with Wizards.
Nintendo of America has denied any wrongdoing. The various companies involved are currently discussing a settlement. You can read more about the case at the link above.