The way the cast was at the start of season 8 you can tell it was on its last legs but
Had Cuddy not left
Had Olivia Wilde not gotten so many film roles
Had Kal Penn not gotten a job at the White House
Spoiler
(though his death was the most shocking)
Then I reckon they could have gotten House to 10 seasons.
There could have been so much more to explore.
But you cant fault them for getting out while the going is good.
But the best thing about House will always be Hugh Laurie getting that comedic 'Blackadder' pigeon hole off his back. We all know he can now do serious acting work. Now lets see him do it over here