It's not very easy to understand Microsoft's strategy for Xbox right now. The company has put itself in a position where every game release will have people with other formats wondering if they need to bother getting it for Xbox or if it will be multi-format.
According to several reports, there are also plenty of people at Microsoft who don't understand the strategy either, but apparently the management still seems to have heard the criticism from the fans. At least that's what the rather credible insider eXstas1s claims, stating that work on PlayStation versions of select Xbox titles has slowed down considerably.
This followed the outcry that arose after Indiana Jones and the Great Circle was announced for Sony's console before the game had even been launched for Xbox. eXstas1s writes that his assessment is that Microsoft will take it easier with PlayStation releases where some games may get this treatment, but not all. In addition, he says he has heard that Halo and Gears of War are considered red lines.