Liuzzi may be under FI contract but i highly doubt he’ll stay. Seat goes to di Resta or Hulkenberg and Sutil wont leave.
Senna’s been ruled out of HRT but still on the list are Klien, Yamamoto and a few others according to Kolles. Probably Klien in this case.
And then Toro Rosso. Alguersuari will stay because he is seen by RBR as the next Vettel. However Buemi had been involved in quiet a few arguements with STR and there’s been talk of him not being there in 2011. The obvious choice to replace him is Ricciardo but he has already stated he wishes to stay in Formula Renault 3.5 and Red Bull say they want him to gain the expoerience of winning that title. So, if Buemi leaves that could open the door to Bruno Senna who has been linked to the seat for a few years now. A year for him to really prove what he’s worth?
Well if Buemi does leave, and they decide to keep Ricciardo in WSBR, then they could go with Heidfeld if they want good results, or with Hulkenberg if they want another young talent that could get to Red Bull. So I imagine that Senna isn’t their first choice, in case they do fire Buemi.