Actually, House isn't dead- David Shore has confirmed that in a couple of interviews. He also mentions Foreman finding House's ID card and says that he believes Foreman is laughing disbelievingly because he figures out what House has done. It would make sense, since Wilson has obviously disappeared too.
I love the parallel with Sherlock Holmes to finish up with- like Holmes, House has 'risen' from the dead and come back to his friend.
I don't want to dwell on what House will do after Wilson dies- perhaps Wilson will seek the treatment that gives him longer to live. Maybe House will some back to Princeton at some point, or at least come out of hiding, act surprised that everyone thought he was dead, do his jail time and move on with his life. I was pretty devestated that they decided to kill Wilson, but at the moment House and Wilson are off having fun somewhere and that's what I'm focusing on.
The show definitely declined in the last couple of seasons- I lost interest for a while after 'Help Me'... but it's been a wonderful series with an amazing lead actor and I will miss it terribly now it is over.