And in a nice touch-for the celeb hosts, the show will donate whatever the total amount won by the winners is that week to a charity of the celebs choice...
I personally doubt Mike Richards really wants the full-time gig- the reason he's doing two weeks is that it probably took a few taping days to decide they'd go the celeb guest host route.
My thinking is-if Ken does this week and next, then Mike does the next two weeks, the 4 celeb hosts announced take them through February. They'll probably do more guest hosts for the rest of the season (some for one week, perhaps some for two); then make the final decision in May and have that person start up full-time in September (perhaps they delay the TOC and start next season with it).