If he accepts:
The Royals have a 2nd baseman whose production is predictable, in a good way. OR, if Dayton Moore doesn't actually want him on the team any longer*, the Royals can release him and only pay 1/6 of whatever the offered amount was. From Bob Dutton:
The Royals retain some financial wiggle room if Grudzielanek accepts arbitration because arbitration-determined salaries are not guaranteed. Teams must pay only one-sixth of a salary if they release a player with 45 or more days remaining before Opening Day.
*most likely scenario
When, errr...if he declines
We get a sandwich pick in next year's draft. Mmmmmm, sandwiches...
Grudz will almost certainly decline the Royals' offer so he can try and get on board with a winning team. He all but said that in this Royals.com article.
Don't get me wrong, I love Mark Grudzielanek. He's, as stated many times, a fabulously professional player who keeps his mouth shut when it's not necessary to talk, who produces consistently on the field, and by all accounts works hard. I realize his numbers aren't the greatest, but to me there's value in knowing what you're getting from a player, especially if your team is otherwise chock-full of question marks.
Grudzielanek was a valuable addition to a club that needed stability somewhere. If he declines yesterday's offer, which I'm almost certain (I'd say about 95-98% sure) he will, I hope he can find what he's looking for, which is the chance to win. What player doesn't want that?
Farewell, Mark. I'll miss you, but I'm also looking forward to that sandwich...pick.