I have two digi bodies, 5D and 400D. When I can afford it, I'll probably get hold of a 1 series and dump the 400. Then it'll be wide angle on the 5D and whatever else on the 1.
At the moment the 400 doesn't get much use. I only take it out as a backup or second if I have a job. For example at the MCG last weekend, I had a 24-70 on the 5D all day, and switched between a 10-22 and 70-200 on the 400D. Definitely a huge advantage over one body.
So, I guess that may not count as amateur use of a second body. But, I'm certainly no 'pro' as yet.
J.