a little poetic license.
Wild guess, I think it will take about 5 years , assuming the concept takes off, to really impact the PC market...think iPhone and how its impacted the cellphone\smartphone market.
Of course the traditional boxes will still be around so if you only do the basics ( email, web, word processing , light gaming )I wouldn't spend a huge amount for a laptop in any case. You pay a big big premium for "state of the art".