The Cisco docs talk about needing to be at a 7.2 version before upgrading to 8.0.x. However, I haven't really found a reason why that is.
I went into my lab and put the same version that my production ASA is running and dropped the same config on it. I then uploaded 8.0.3(6) and booted. I've seen no errors. All commands took. I upgraded ASDM as well.
By the way, I'm upgrading to 8.0.3 for the eigrp features. Anybody know why I wouldn't be able to go straight from 7.0x to 8.0.3??