Lost: Neverending story problems

Don't get me wrong, I love Lost. It's still a great show, but it is / could be facing a huge problem:

Link

Lost needs to have an ending season. They way they are going right now, I think a fourth, and final season, would be great.

Why?

If Lost is allowed to go on for season after season, it will inevitably start to increasingly SUCK ASS.

This happens in TV, books (like the Wheel of Time that never ends, 12 novels and growing...), where more and more plot lines are introduced just to lengthen the TV show / book series, and fewer and fewer older ones are resolved.

Please ABC, don't do this to Lost. It deserves better.