Research In Motion has already confirmed that its PlayBook tablet will be upgraded to BlackBerry 10. It today reconfirmed this via Twitter and added a general timeline:
Cascades support for PlayBook will come w/ the PlayBook OS upgrade to BB10, shortly after launch of 1st BB10 smartphone
RIM has only so far indicated that the first BlackBerry 10 device will be launched in the latter part of 2012. Recent rumours suggest that it could be formally announced in August with a launch to follow sometime in the first half of October. BlackBerry PlayBook owners can probably expect to be running BlackBerry 10 by the end of the year.
RIM has also confirmed that BlackBerry 7 devices will not be upgradeable to BlackBerry 10.