30 Rock stepped outside its usual genre and did a spot-on satire of all those ridiculous Housewife shows on Bravo. Earlier this season, one storyline was that Mrs Tracy Jordan had gotten her own Bravo TV show. If I recall, it was part of the Kablevision "synergy strategy".
Since Tracy Morgan was sidelined by his recent health issues, it was a clever way to incorporate his absence while doing a sendup of those awful candid reality shows. Sherri Shepherd, whom I generally dislike, will probably get an Guest Actress Emmy nomination out of the episode, especially since actors just love to mock the reality shows taking away jobs.
Several months ago, 30 Rock was renewed for next season, so even if ratings tanked against sports last week and next week, it's still one of NBC's few hits.