Better late than never. It seems like Jay‑Z did a cameo and joined Kanye at the latter end of the Glow in the Dark Tour in Madison Square Garden (August 6, 2008). Then, after their performance of Jockin’ Jay‑Z, Jay‑Z announces his next project, Blueprint 3. Sick.
PS. Note: If you happen to click on Rainn Wilson’s and/or Jenna Fischer’s linked-names above, it’ll take you on their MySpace page. There, have a listen to Petra Haden’s cover of Don’t Stop Believing by Journey. Pretty interesting arrangement but very compatible to The Office’s storyline and humor.