I am not aware of the service life of the 40D and I'm sorry that you have experienced a failure, its never a good feeling.
I dont think it would be worth the fix. IMO i would just get a refurbished 60D through the Canon Loyalty Program. I believe they are going for around $650. So why repair a 40 when you can upgrade for 150 more than the repair cost?
Be Content with what you have; rejoice in the way things are. When you realize there is nothing lacking, the whole world belongs to you.