don't think anyone is really trying to kill the tablets, i believe its the manufactures not willing to subsidize them. Cheapest way is to buy them full price and go with the pre-paid MiFi or another mobile broadband router to give you access on the go. I have a Virgin Mobile MiFi i got used, data is only $30 for 30days for 2GB data. and its pay per use, so if i don't need it one month or more then i dont worry about it. Plus the ability to share with other devices helps too.
Long story short, there are other alternative options then built-in Cellular tablets.
Thinking about a playbook myself and @$199 and being smaller then my iPad, im not going to think twice.
i3-2100, 8GB, 90GB Vertex3, 1.5TB HDD, HD6850OC, 23"ACER LED Monitor (Gaming Rig)
1.83ghz Macbook 1,1 (School work, Websurfer)
4GB Mini, 2GB Nano, 30GB Video, 8GB iPhone 3GS, iPad1
BB Bold 9900