These are for flights in early 2014, and can be found directly on American’s website (http://www.aa.com/). There is a visa required for US citizens, but if you’re transiting to another country within 72 hours, this requirement can be waived. If you don’t specifically want to visit China, you can book these flights and then book a cheap intra-Asia flight to another country, as long as it departs less than 72 hours after you arrive in Beijing.
This deal won’t last long – it’s pricing out without some of the extra surcharges that airlines typically add on to international flights, so it probably won’t be long before they realize this and correct it. If you’re interested, book now!!