Adobe wants Microsoft to remove the feature and offer it separately for a fee. Microsoft has agreed to remove the feature but is unwilling to charge for it. Since Adobe claims PDF is sort of open, it's not clear why. However, the WSJ says "Adobe declined to clarify its exact objections to Microsoft's use of the specifications."  Microsoft already distributes Adobe's Reader program with Windows, and recently patched one of its security flaws -- probably the first time Microsoft has patched someone else's application via Windows Update.