According to ESPN's Josina Anderson, cash flow is the main demand for Kam Chancellor's holdout. Anderson posted an explanation of the situation on her facebook page:
I'm told what would help assuage Seattle Seahawks S Kam Chancellor's holdout is better cash flow over the first two years of the remaining three on his current deal. One way a cap-tight team that's relatively cash-rich can hypothetically achieve this would be by converting the majority of the $9.65M Chancellor is due in base salary over the next 2 years to signing bonus. Ideally this could be paid out five days after the contract is executed, or perhaps by remitting $3.5M early and another $3.5M by Oct. 1st. It should be noted that about $4.45M of the $4.55M in base salary that Chancellor is due in 2015 is already guaranteed.
In other words, Kam wants the Seahawks guarantee the next two years of his contract, and pay him for it up front (it would be pro-rated over the length of the new deal so the cap wouldn't jump).
It would be similar (on a much larger scale) to what the Seahawks did for Marshawn Lynch last offseason. Lynch held out last year when he was due $5 million in base salary with $500,000 in per-game roster bonuses and another $500,000 in incentives.
Seattle mostly held firm to that deal, but converted those per-game and incentive bonuses into a a guaranteed part of his contract (so, $1 million total). They also transferred $500,000 that Lynch was due to make in 2015 into the 2014 season. All told, he got a raise of $500,000 plus saw his per-game and incentive bonuses become guaranteed money.
While Seattle may do something similar to what they did with Lynch, Kam's asking for a lot more, per this report. We'll see how much resolve both sides have on this. Seattle obviously does not want to make things messy with Chancellor -- he's been a model player and teammate -- but they have good reason to simply say no: precedent.