That's the word from EW.com and Michael Ausiello:
Sources confirm to EW.com’s Ausiello Files exclusively that Chad Michael Murray and Hilarie Burton, whose characters tied the knot in last night's penultimate episode, will not be returning for the show's seventh season next fall. The CW is expected to formally announce their departures next Thursday at its "upfront" presentation.
Murray and Burton have been engaged in rather high profile contract negotiations for the past several months. Ultimately, a deal couldn't be worked out and both actors will make their final appearances in next Monday's season finale.
To fill the void next season, a Tree Hill insider tells EW.com that two new characters will be introduced. Additionally, Austin Nichols (Julian) is being promoted to a series regular.
Full story on EW.com: http://ausiellofiles.ew.com/2009/05/exclusive-murra.html.