It's definitely coming. Look what they did with the new Mini though, they pulled the optical drive, but that allowed for more options--faster processors, dual hard drives, upgraded graphics cards, and a lower price point.
If you (or anyone) needs to burn physical discs, there are plenty of external options available. There are also a lot of people who want Blu Ray capability--along with a lot of people who don't care about things like that. By removing the optical drive altogether, it lets the end user decide what they want or need without building space/cost consuming options that are quickly fading from necessity into the machine.
It might become a little bit more inconvenient to burn home movies to disc, but with room for upgraded CPU's & GPU's they will become a whole lot easier to create in the first place.