I think Quinn, and as a result maybe Masuka, are going to get involved next season.
At first I thought Dexter was going to answer Batista's phone when Quinn called which would have been wild. I have no idea how that would have helped, so it's probably good that it didn't happen, but it was so close.
I'm guessing Quinn is going to visit NYC to collect Batista's body and talk with the NYC Detectives. I forget who has Batista's phone, if Dexter left it behind or not, but either way I'm guessing they'll look into his phone records. The last call Batista's phone made was to Harrison's phone, which will lead to Quinn talking to Harrison and eventually Dexter.