The official press release from the Gresini Press Office announcing they will be racing at Valencia:
SAN CARLO HONDA GRESINI AND GRESINI MOTO2 WILL PARTICIPATE AT VALENCIA AS TRIBUTE TO 'SUPER SIC'
Both teams run by Fausto Gresini will be represented on track this weekend. Hiroshi Aoyama rides in MotoGP, whilst Michele Pirro and Yuki Takahashi will compete in the final Moto2 race of 2011.
Fausto Gresini "The decision to participate was not an easy one, but we have made this choice as it is what Marco would have wanted. Going out on track at Valencia is definitely the best way to honour him by doing what he most loved to do: Ride and experience the world of MotoGP. This is why I believe that the best show of affection that we can make to Marco is by lining up our teams and riders for this race. ‘Super Sic' will be present in the hearts of Hiroshi Aoyama, Michele Pirro and Yuki Takahashi, and I am sure that they will give him a most fitting tribute with their performances on Sunday."