There is some data that suggests that black bear attacks are more likely to be predatory than brown/grizzly bear attacks.

Brown/griz attacks tend to be most often defensive in nature (from the bears perspective). Because of their great size and strength these bears can do incredible damage in their first attack, but once they perceive you to be no longer a threat, they will retreat. (The important exception to this would be a brown bear defending a food cache, a moose kill for example.) Hence the advice that in a brown bear attack, if all else fails, as a last resort curl up and play dead.

Black bears are in general more timid than brown bears, and more likely to run away without attacking. However, when black bears do attack, there is good evidence that in many of these attacks the black bear is acting as a predator and you are lunch. Hence the advice that if attacked by a black bear, DO NOT PLAY DEAD, but rather fight back with any means available.

This means that if traveling in areas where both black and grizzly bears might be present, one should take the time to learn how to tell them apart.

As has been noted by others, one of the best sources of information on this stuff is Stephen Herrero's book "Bear Attacks: Their Causes and Avoidance". Herrero is a professor of Biology and Environmental Science at U of Calgary in Alberta. He is a world recognized expert in bear safety. In my opinion it is a must read for anyone living, working, or playing in bear country.

Herrero says he has found no association of rabies with bear attacks. It could be, but he has not found evidence of it.