It seems that it is impossible at this point to have a conversation about Strikeforce that doesn't involve quickly pointing out that the Gilbert Melendez is stuck there with no competition. Some of that noise was lessened when Melendez was put through a hell of a test in his third fight with Josh Thomson at Strikeforce: Barnett vs. Cormier, but most people recognize that Thomson is a legitimate top-end lightweight when healthy and firing on all cylinders.
UFC president Dana White was on HDNet's Inside MMA and the subject of Melendez came up. White had this to say about Gilbert's future:
Strikeforce is not going anywhere. And Gilbert Melendez is not going anywhere. He will fight again on Showtime.
It's a tricky situation with Melendez. He is the one who chose to sign the extension with Strikeforce prior to Zuffa (the UFC's parent company) purchasing the promotion. They threw a big deal his way and he signed it and made the decision at that point that he was willing to be the big fish in a small (maybe medium) pond.
At the same time, Melendez is a high level talent who should be fighting better opponents than the Strikeforce roster can offer him. Aside from the legitimate test of Thomson, there's no one else at 155 that would seem to have anything to offer the champion.
So, knowing that they could bring him into the UFC and allow a top three 155'er to fight the rest of the best fighters in the world, but aren't doing it, is frustrating.
The reality of the Showtime contract and needing to have attractive "draws" on the card is also of high importance so it's not impossible to understand why Zuffa isn't ripping Gilbert from Strikeforce and throwing him in the UFC where he isn't likely to move the needle significantly on a PPV show. Maybe, had Strikeforce been built up as more important (maybe an impossible task), the idea of an eventual champion vs. champion fight would be able to do a little business. But, for right now, the idea of needing Melendez in the UFC is something that appears to matter much more to the hardcore fans than it does to everyone making decisions.