The rot of corruption in Kenya has set in to such an extent that really tackling it will require a national leader that is not beholden to the usual "mafias". But the maths of tribe-based elections mean that it is unlikely that such a leader will appear in Kenya in, say, the next 50 years. So the sort of top-down leadership that one would normally expect in such cases is out of the question for quite a long time.
As things stand, devolution offers the best chance, given that people get to see the eaters right there, on their doorsteps, and will, one hopes, get more worked up and demand changes. Nevertheless, even devolution will take a long time to work because at the first cut, corruption itself gets devolved and the tribal maths gets devolved into clan (or sub-tribe) maths. Kisumu County is an instructive example here.
Kenyans should simply resign themselves to their country becoming another Nigeria and worse. The only hope one can see on the horizon is that the populace will evolve to the point where character and integrity are considered when choosing leaders, the biggest thieves are not the most admired people, etc.
