You missed a few things by coming in this late. The good news is an article I read several months ago hinted that they have a story line worked out for the next 3 or 4 years. So as long as folks keep playing, and Bioware keeps making money, there's no reason not to.
People have been sounding the death of this game since it first came out. But like the scrappy fighter in ever cheesy boxing movie ever, it just keeps coming back for more.
Besides, it's ****** ******* Star Wars!