Once he joins Microsoft's ranks, Russinovich will begin work in the Platform & Services Division as one of Microsoft's 14 technical fellows. There, InfoWorld says he will "help chart the future direction of the Windows platform as it adopts new virtualization, security and multicore processor capabilities." The other Winternals co-founder, Bryce Cogswell, will become a software architect in the Windows Component Platform Team.
As for Winternals—and the company's freeware site Sysinternals—Microsoft hasn't made an official announcement regarding their fate. However, Russinovich believes development of Winternals utilities will continue in Redmond. Support contracts for Winternals software will not be renewed, however, even though Microsoft does plan to continue supporting customers through the end of their existing contracts. Thanks to readers FroBozz_Inc and JT for the tip.