Nakamura finished up strong beating Giri and drawing Grischuk. A Grand Prix player can choose the best results from 3 of his 4 designated events and the worst one is disregarded. So, Nakamura can still be in the running. His next GP event is in Lisbon on April 17, 2013.
He is currently ranked 10th in the world with a FIDE rating of 2763.7.
Good luck GM Nakamura!
N.B. Info above is from memory. If incorrect please post correction. Thanks. Dan