While their strong live crowd reactions at the Royal Rumble could convince WWE to more extensively book Booker T and Kevin Nash for future television, neither is expected to wrestle with WWE for the long-term.
According to F4WOnline.com, Booker T is under a WWE contract, although the word prior to Sunday was that he was mainly being eyed as a potential manager or “Tough Enough” coach. The idea of Booker T wrestling in a veteran role is certainly on the table, but he was definitely expected to be prominently involved in other areas of the company.
With Kevin Nash, there definitely is no long-term deal in writing, and additional use of the long-time Superstar (beyond the next few television shows at a maximum) would likely be a consequence of the crowd reaction. WWE did hint at something between Nash and Big Show, but it is unclear that such a match is indeed in the WrestleMania plans.