Based on this article on AllAfrica.com, Kenya, Uganda, Rwanda, Burundi and Tanzania will soon launch a campaign to promote the region as a single tourist destination.
This makes sense. Instead of each country using its resources to promote itself, combining forces will mean a higher marketing budget and a stronger impact. Travel agencies can also come up with packages that are not limited to a single country but that can take tourists to destinations located in multiple countries within the region.
Of course, administrative matters such as visas will need to be sorted out first. Hopefully this does not remain a political wish, and that we see this coming into action very soon.