Citation needed. The original Galaxy Tab sold ~2 million in the first 3 months, the Playbook sold ~250k in the first 3 months. [1]. Were Windows tablets selling that well?
[1] - http://www.bgr.com/2011/05/18/250000-blackberry-playbook-tab...
Hardware has changed radically. Old tablets had battery life of 3 hours, new tablets 8-10 hours. Old tablets weighed 4lb, new tablets 1lb. Old tablets needed a stylus or used poor resistive single touch screens. New tablets use responsive multitouch screens. Old tablets were dependent on wifi and did not have GPS. New tablets can have constant connectivity and can include awesome location based services. Old tablets cost ~$1k or more. New tablets cost < $500. Old tablets mostly ran Windows that was relatively poorly adapted to tablets. New tablets run beautiful dedicated tablet OSes.
There's just no comparison at all between these products, there's no way you can just make an assertion about the market for them being the same.
From: http://ngadgeti.blogspot.com/2008/04/hp-pavilion-tx1209-revi...
With that said, I think its absurd to say that the market for non-iPad tablets is the same today as it was 18 months ago. People are definitely more interested in tablets now. I wouldn't be surprised if there were 50M tablet PCs with Win8 sold next year.
But during the company’s quarterly earnings call on Friday, a Samsung executive revealed those figures don’t represent actual sales to consumers. Instead, they are the number of Galaxy Tab devices that Samsung has shipped to wireless companies and retailers around the world since product’s formal introduction in late September.