He's going to get a lot, in the range of $6 mil per year on a long term deal. The Kings can afford it though, he's not a UFA until the summer of 2013, and they can potentially shed any of Penner ($4.25 mil), Gagne ($3.5 mil), Stoll ($3.6 mil) or Scuderi ($3.4 mil), who all become UFAs between now and 2013.
Quick is the last star they need to lock up, as Kopitar, Doughty, Richards and Carter are all locked up for 4-10 more years at their current cap hits, Williams is locked up for 3 more years at his current cap hit, and Brown, Mitchell and Greene are all locked up for 2 more years at their current cap hits. So, they should be able to splurge on Quick if necessary, while still keeping their core together, and just dropping 1 or 2 of their current highly-paid-but-less-integral players who are set to become a UFA between now and 2013 (Penner, Gagne, Stoll or Scuderi).
With how streaky goalies are (even over long stretches, like say two seasons), I'm always wary of teams giving too much money to their goalies, especially on long contracts. However, the precedence has been set; Quick could easily get close to Rinne's cap hit and could get 7 or more years.
Whether he does or not depends on how much of a discount he's willing to take to keep the team out of cap trouble, how much he wants to stay with that organization (behind the scenes stuff) and also by how the goalie market is shaping up prior to next summer. I'd say no less than $5M/yr and no more than $7M/yr; A pretty safe estimate.