The major network Upfront presentations won't roll out until next week, but most of the big five have already shored up a number of new and returning series to be presented at the coming events. And while certain series like ABC's 'Castle' are considered a lock for next season, new rumors suggest that ABC may opt to renew the Nathan Fillion-starring detective drama for a full two seasons, much as FOX did for 'Glee' earlier this year. Get the scoop on 'Castle's future early inside!

It remains to be seen if this year's network Upfront presentations will include and major surprises, but things are certainly looking strong at ABC. In addition to the almost-guaranteed pickup of Marvel's 'Agents of S.H.I.E.L.D.,' Deadline claims that the network may opt to renew its strongest drama performer 'Castle' for an additional two seasons, rather than the guaranteed sixth year.

Having struggled in its early years, the Nathan Fillion/Stana Katic procedural has currently begun ramping toward its fifth season finale, and would potentially join FOX's 'Glee' as one of the rare instances of a two-season pickup. Other locks for ABC renewals in the coming weeks include 'Grey’s Anatomy,' 'Scandal,' 'Modern Family,' 'Once Upon A Time,' 'Revenge,' 'The Middle,' 'Shark Tank,' 'Dancing With The Stars' and 'The Bachelor.'

We'll find out for sure in the coming days, but what say you? Does 'Castle' deserve the security of a two-season pickup? Are you as bitter as we are Nathan Fillion didn't get this much love when 'Firefly' was on the air? Sound off in the comments!