In response to Gericom - The idea was that House didn't plan to fake his death before the almost drug overdose, but that he did it after he escaped the fire. He would not have been able to fake his death without the body of the other guy so the show leaves it to yoru imagination that he snuck into the hospital, fixed Foreman's table with his nametag as a clue for him to find and switch the dental records with his former patient's body.
UPDATE: David Shore answered some post finale questions.
House is NOT dead is the most important part to take away from it. The play on Foreman of finding his nametag under the table was used as a device to show it was not just a delusion on Wilson's character.
Likewise, I love the show but the ending just didn't live up to my high expectations.. Definitely worth a watch and see for closure but I wanted more of an emotional episode just like when Amber died. It didn't give me that feeling, but I will never stop loving this show!