Just returned from 2 week safari in East Africa with 3,000+ photos. Primary gear was Canon EF 70-300 f/4-5.6L IS on 7D body. Was light limited more than focal length limited for the most part, particularly on late afternoon drives. You can always capture wildlife "in context" which often leads to as interesting a shot as frame filling face and shoulder portraits. And, with 18 Mpxls you can zoom by crop and still have a lot of pixels for printing. For wide angle, I carried a Canon Powershot G12 - a good weight/quality/size trade-off and avoided changing lenses on the 7D during dusty game drives. Do agree that careful pre-planning for a "once in a lifetime" trip is crucial.