I'd take a gamble and say probably not. Usually, companies upsell products halfway through their lifespan, and considering the $300 discount that has been going on since December, I'd like to think we've just reached the halfway point.
As far as improvements go though, I'd love to see them make the pop-up flash be made of Alloy as well. Everything else has already been suggested it would appear.
P.S. Willing to take a gamble and say that more than likely, the sensor will indeed change. Maybe not to the 24MP Anvh mentions, as that would oust most FF Cameras for resolution.(Which would be absurd, to say the least), but at least an 18MP sensor, to make it more "Competitive" in the pixel count area against the Canon APS-C Models.
All I know for sure is, won't bother upgrading unless they make something immensely better about it. Quite happy with my K-5