I still think 9 is the perfect number of cogs and I have 10 and 11. 12 is just silly but I guess they have to keep coming up with new stuff. By the time they hit 13 you'll probably have to buy new wheelsets again.
What they need to come up with is some high tech superlight 15 speed IGH hub with electronic shifting instead of adding a cog and even narrower weaker chains every few years.