According to game site IGN's Wii podcast, the Wii MotionPlus is delayed. According to Nintendo, it's not.
The IGN podcast, which is often privy to Nintendo announcements before they're announced, stated, "Nintendo is internally struggling with Wii MotionPlus, trying to figure out a few hiccups."
These "hiccups" would mean that Wii Sports Resort would be pushed back along with the Wii MotionPlus add-on. This would make sense someone as the game is MIA on Nintendo's upcoming games list.