It appears the the 1-port and 2-port connectors use the same 30-pin pinout (see slide #9) :
http://www.vesa.org/wp-content/uploads/2010/12/DisplayPort-DevCon-Presentation-eDP-Dec-2010-v3.pdf
However, I read in a Lenovo forum of a guy trying to put a FullHD panel in a 1366x768 laptop, a U430. He tried 9 different cables from many different FullHD thinkpads and eventually settled on a U530 connector because that device came with a FullHD screen.