Nick rakes in a lot of money with this show, so they would very likely have this running for some more years to try and gain even more green to fill their vault with huger sums of cash/simoleons/possibly even some gold bars.
This show has a huge popularity scale and a huge fanbase, so knowing Nick and their profit goals, I don't see this show getting canceled anytime soon, as long as its still running, they can rake in more greens, even if they make new episodes that are poor in quality or have mediocre plots.
I would like to see this show end great soon though with a finale epiosde that is very good, because a lot of the episodes they've played since around 2005 or 2006 suck @$$!