Miley Cyrus's 'Saturday Night Live' preview

Miley Cyrus will host this weekend's "Saturday Night Live," which means jokes about tongues and twerking and corrupting the nation's youth -- and in fact, said jokes are already here, via her "SNL" promos with Taran Killam, which arrived last night.

She will also double as musical guest. Bruce Willis is host next week -- he will not double as musical guest.