Tough choices

My reliable old companion, Canon 30D has come to its end. I bought it second hand and proceeded on using it in all kinds of conditions for every cent that I paid for it. I put the poor camera thru a lot of abuse and it kept on going. Now I have to sadly say that its shuttercount has reached it's limit and I need to find myself a new camera.
The problem is that I don't know which camera to buy. Well, I do know that I will stick with canon, simply because of all the lenses I have. I don't feel like changing all my gear, getting a new camera body is expensive enough. From all the camera models that canon makes, I can rule out all of the 1-series bodies, I simply cannot afford to put that much money into my hobby. 100-series cameras feel small, light and just aren't up to the task I have in mind in some areas. That leaves me with the "ten block" and here is where the problem begins. I really don't know if I should buy a new 40D,
a 50D or maybe look for a bargain on a used one, in which case a 30D could be considered also.

I would be very grateful for any comments and ideas on what to do, especialy if opinions are backed up with reasoning and facts.