There is another problem and that is the production and supply of Lithium. The price will go in one direction and that will reduce the use of Li-ion batteries as the price will increase.
Check out these articles http://www.galaxyresources.com.au/documents/LithiumforSecondbatterywilldryupin16years_000.pdf
and http://studentweb.stcloudstate.edu/lipa0401/Lithium..pdf
10,000 recharges over the course of 20 years.Not bad. The batteries in Kindles probably have an undeserved bad reputation. The reason hardware makers use batts that can only be replaced in-factory is to increase the time between charges, thus the 17" MacBook Pro lasts a long time on a charge.
Thanks for the link.