The issue about assignability of contracts is more complicated than Shawn Schatze of fightlinker makes it out to be.  He is referring to Frank Shamrock's contract, which you can see here.

The provision in question states:

Pro Elite shall have the absolute right to assign, license, or transfer any or all of the rights granted to it hereunder without fighter's consent or approval, however, Pro Elite must obtain fighter's consent, which cannot be unreasonably withheld, to assign, license, or transfer Pro Elite's right to promote any bought of fighter.

The bolded sentence here actually suggests the opposite of what the fightlinker post says.  This clause is in very few Pro Elite contracts.  I have seen other ones that do not have that sentence, only the stars got a consent clause in their contract.  

There's a reason Coker has said there can be a business solution or a legal solution.  The bottom line is that for most fighters without the consent clause, Strikeforce has a very strong legal position in favor of assignability.  As for fighters with the consent clause, their position is weaker.  However, even where there is no consent clause, boilerplate language favoring pro elite is not the beginning and end of the story.   These contracts are in California, a state where courts strike down any no compete clauses in standard employment contracts even when employees knowingly signed them.  

Assignability in this case, where the new company is almost exactly the same as the old, is unlikely to offend a court in a way that would lead to it being struck down as a matter of public policy.  This is unlike being assigned to a completely different line of work.

Fighters attempting to challenge assignability have an uphill challenge, but there's a reason Strikeforce isn't just telling fighters like Carano to stick it.  They are renegotiating because their position isn't completely bulletproof, and they'd rather come to a deal than end up in litigation.  I haven't seen her contract, but my guess is she has one of these consent clauses.  

My hope is they just work all this stuff out and find a way to avoid the courtroom.  I've spoken with 4 lawyers about the assignability of these contracts, and the opinions have varied.  That only suggests to me that litigation would be long, drawn out, and a major waste of time.  I believe they'll work it out.  

Update:  MMA Weekly's insider blog has a report that Jake Shields may not be on board with Strikeforce:

Though Coker says most of Elite's "top 12" fighters have given assurances they will fight for Strikeforce, it's former welterweight champion, Jake Shields, is not yet committed to the San Jose-based promotion.

"We're still in negotiations," Shields' manager and father, Jack Shields, told MMAInsider late Sunday night.

"Just like with Randy's deal, when he was in the situation with the UFC, to do a declaratory (ruling), it's going to be another six months for these fighters, and then we'll be forced to take them down that path, and the fighter's not going to fight for six months, and the court will rule one way or another.

Jake Shields was always the most likely holdout.  He's made it clear he wants to go to the UFC, and there are no relevant 170 pound challengers for him in Strikeforce.  Shield has a tough decision to make now about whether he wants to fight this out in court or just settle for Strikeforce under his current deal.

I can't be sure about Jake's contract, but the public Frank Shamrock contract doesn't mention a champion's clause.  If there's no such clause, his current contract isn't much longer, and he may be able to just fight a couple times and leave in the same amount of time a costly court battle could take.

Of course, I said the same thing about Couture back before his litigation, and he ended up blowing through an incredible amount of money only to end up back in the UFC.  Frankly, Jake can probably increase his stock with a couple of big wins on Showtime or CBS, and then move over to the UFC.  He still has room to improve anyway before taking on guys like St. Pierre, Fitch, Alves, and other top welterweights.