When will 10k become the norm? Like when 7200rpm did? It seems feasible since a lot of the scsi drives are 10k and 15k and the raptors are 10k on sata.
Id bet never
the "norm" isnt "performance space"
and other advances are just as likely to offset the added advantage of rotational speed to cost ratio
areal densoty isnt likely to increase much in the current technology either
but other schemes are being developed