I need a new motherboard, how long is delivery-time?

I am new with apple and since october 2006 the owner off a i-mac intel '20. 3 weeks ago he won't start-up the screen stays black and apple care take the machine for repear. My computer needs a new mother board.
Not a good start for a switch like me, I was glad all my data was still on my windows laptop to.
The apple service station can't tell me when the new motherboard should arrive.
Has anybody from Holland the same problem with long waiting time for delivering.? is this normal in apple world?
What should I do ?

greetings
Rob Holland ps sorry for my terrible english