Roger Wardell, an insider of Marvel comics and Marvel Studios posted these two tweets 3 days ago:
ItÃ¢â‚¬â„¢s quite a simple equation if youÃ¢â‚¬â„¢re ready to make a big leap of conjecture over a cliff of confusion. You get the massive full-blown rumor that Viggo Mortensen could appear as Doctor Strange in Thor: The Dark World.
Roger Wardell has been known to release big announcements like these before Marvel does and most of the time he is always right. Personally im excited about these news because i have always been a huge fan of Doctor Strange. I cant wait till i hear more news and hopefully maybe sooner then later first images of the Sorcerer Supreme himself.