• Facebook testing out a piece of information that would be very valuable to marketers: The "want" button.
• It was discovered by Cut Out + Keep that the button has been added to the Facebook Javascript SDK, but the button will only work on the Open Graph on something marked as a "product".
• Facebook's released a statement: "We're always testing new Platform features, however we have nothing new to announce."

From the article:

Facebook might be making it easier for brands to utilize “Want” buttons (and may be closer to a killer ad option for retailers), according to an InsideFacebook.com report. The Facebook-dedicated news blog says developer Todd Waddington from Cut Out + Keep has discovered that Want buttons can be implemented on Open Graph items marked as “products.”

When asked about the report via email, a Facebook spokesperson replied, "We're always testing new Platform features, however we have nothing new to announce."