UPDATE: I'm told arrangements were made by none other than Jerry Seinfeld himself for Michael Richards to go on Letterman by remote satellite feed tonight. "Kramer" made a major apology on Dave's Late Show which had Seinfeld scheduled as a guest already. Richard's appearance during Seinfeld's interview was treated as a surprise. Kramer made a complete mea culpa, and sources at the taping told me that both Letterman and Seinfeld seemed to accept what he was saying as genuine remorse. Mostly, Richards looked embarrassed. I'm told the Hollywood people around him jumped into action "to avoid a Mel Gibson delay" whereby that apology was not made in the same news cycle or complete enough.

Richards on Letterman to apologize