As Malcolm Tucker was a rather late Star-Making Role for Peter Capaldi there are many examples. Malcolm caused this for people who saw Peter Capaldi in Torchwood as the much more sympathetic civil servant John Frobisher, the still sweary but more tragic Mark Jenkins in Skins, or way earlier than that as the Angel Islington in Neverwhere, or still earlier as the Adorkable Danny Oldsen in Local Hero.
Region 1 DVDs are coming out in August 2013, and BBC America has aired episodes, albeit heavily bleeped.
Shout-Out / Take That: The season 3 episode in which Nicola and Peter are interviewed by Richard Bacon contains references to two other Five Live broadcasters, Simon Mayo and Mark Kermode. The reference to Kermode is only an off-hand, blink-and-you'll-miss-it comment about his supposedly "massive" hands by Ollie, but it seems to have taken on a memetic life of its own around Kermode.
The show takes fairly regular potshots at Top Gear, especially Phil being disparagingly compared to James May and Malcolm saying Richard Hammond needs a punch in the face. In another episode, Malcolm says that he hates Steve Fleming "as much as James May presumably hates himself."