Yep, looks like P-51 wing, but it didn't handle well, so it was cancelled.
The new wing was fitted to a modified Spitfire XIV NN660, in order to make a direct comparison with the earlier elliptical wing, and was first flown on 30 June 1944 by Jeffrey Quill. Although the new Spitfire's speed performance was comfortably in excess of an unmodified Spitfire XIV, the new wing displayed some undesirable behaviour at the stall which, although acceptable, did not come up to the high standards of Mitchell's earlier elliptical wing. NN660 crashed 13 September 1944, killing pilot Frank Furlong. No reason for the loss was officially established.
http://en.wikipedia.org/wiki/Supermarine_SpitefulBoth the Spiteful and Seafang production orders were cancelled, as conventional winged Spitfire and Seafires were easier to construct. In all, only 17 Spitefuls were built, and two Seafangs.
http://1000aircraftphotos.com/APS/2918.htm
