Strongly disagree. When I see those little sparks of delight in my mother's eyes when she is using her iPad I think I see a pretty strong predictor of Apple 'being onto something'. Tablets are not about being great multiple-purpose devices. They're about being good enough.
That has best buy saying tablets are cannibalizing their netbook revenue. This does not mean that netbooks or laptops are dead - personally for the current price I find something like an ACER1215N a lot better value for my usecases than an ipad. This is primarily due to the the HDMI out, USB input for storage, rich client gaming and the fact that I can run any VM for any OS I want. For running MS office / Openoffice also the tactile keyboard is handy without paying for additional accessories.
If there are others like my netbooks/laptops may decline but not die completely, I would suggest a 60/40 split in 3 years tablets/laptops respectively.
If you're pointed at data which suggests that laptop sales are declining significantly in parallel with the increase in tablet sales, I think you need to provide an argument a little more substantial than bluster.
There would seem to be some evidence that some of the people who have to choose now are migrating to tablets but the real test will be when they come to replace them having experienced both. Do they stay tablet or return to a laptop?
I was extrememly surprised at the number of people at Singapore's Changi airport who were using their (Apple) tablets in the departure lounges. Still a small percentage of total laptop users, but very noticeable.
And the number of kids showing their parents how easy it was to be online with iPads in the various shops that were selling them.
Step outside the bubble yourself - "most people" don't understand the complicated "Start" menu - they just want to get on with using the web so they can do their internet banking, buy cheap airfares or look at gossip sites. Preferably not at desk. Or with a keyboard.
Step outside the bubble for a second. Most people don't have tablets, and don't want tablets.