From NBC's Chuck Todd and Mark Murray
This is interesting: Rush Limbaugh is bothered by Thompson doing Leno for his announcement.

VIDEO: NBC Political Director Chuck Todd offers his first read on Fred Thompson's official announcement.

Limbaugh said yesterday, "... I'm not crazy about presidential candidates announcing their candidacy on these late-night shows, Leno or Letterman.  I know why they're doing it... The one thing about it that bothers me -- and I'm not rooted in fuddy-duddiness here, although it may sound like it to some of you but -- is I think the office of the presidency has a certain stature, and I don't like to see it linked or tied to pop culture.  Pop culture is by definition one of the low common denominators of our society."

More: "You know damn well that presidents don't go on The Tonight Show. So why should they as candidates? When you link the stature of that office to the pop culture, I don't think the damage is instantaneous, but it's just a slow erosion of the stature of the office.  It's just my instinct here. It could be anybody. This is not directed at Fred Thompson."