Wow 3 days since publishing and I'm the first to comment!
For this articl to be more interesting stating some actual sales figure would be getter than loads of percentages up/down.
As for netbooks; I think the reason the sales dropped has little to do with tablets, tablets are for media consuption, creation being tedious at best on these devices. Netbooks are for people who may want to do more with the device other than browse, email and such.
The main reason I have not yet bought a netbook is thst they are just a little to limited in performance, if a AMD Trinity box appears that would almost certainly change that opinion.
Personnaly I think Intel's Atom chips had more to do with strangling Netbooks than the rise of Tablets, and Ultrabooks are just too bloody expensive.