I'm also on the bandwagon for the Kruger Park in South Africa. It was very well controled and managed in 1997 when I last went. South Africa is deteriorating along with the rest of Africa but from a much higher base.
Try to swing through Cape Town as well. South Africa is on my B list of safe countries, Kenya is a C where:
A - As safe as it gets (U.S, most of Europe, etc..)
B - Mostly safe (Thailand, South Africa...)
C - Safe enough for smart travelers (Kenya, Vietnam...)
D - Not so safe (Tanzania, Egypt, Indonesia)
F - You're asking for trouble (Columbia, Congo...)
When is Disney going to buy up a few African countries and make going to game parks a mainstream vacation?