The day that optical discs die cant come soon enough. Many people are already at the point where it is superfluous technology, unfortunately the mass market is not there yet. If you want to make more productive use of that space you can remove the ODD and install a second hard drive in its place.
For many of us who care about quality, the death of optical discs is very far off. Why? Video.
Standard definition video downloads still don't even come close to DVD, and they can't be upscaled to higher resolutions the same way DVD can.
High definition video downloads can't even really be called "high definition" when compared to blu-ray disc. iTunes downloads don't even contain half the amount of pixels compared to what blu-ray offers, and they're generally encoded at 4.5Mbps (compared to blu-ray's ability to handle video bitrates up to 45Mbps). Plus you get sub-DVD quality audio out of "HD" movie downloads, if it even has 5.1 sound, compared to blu-ray's sometimes lossless and sometimes uncompressed audio. Even when blu-ray has only a lossy audio track, its still encoded at twice the bitrate of iTunes download, if it's Dolby Digital, or uses the same 1.5Mbps DTS track that was used in theaters.
Theres also the issue of bandwidth. Even if you have Charter or Verizon's fastest connections (60Mbps Charter, 50Mbps Verizon), it would still take about the length of the movie to download it, if it was blu-ray quality. When you consider the fact that the average US broadband connection is only 3.9Mbps, its going to take longer than the movie is to download just an iTunes "HD" film.
And don't bring up "better video codecs" or any of that. Blu-ray already uses H.264 (same as iTunes) and VC-1. It's just encoded at a substantially higher bitrate. I mean, let's be honest here, iTunes "HD" downloads don't even compete with properly upscaled DVDs because of the low bit-rate and poor encoder used. Even x264 (open source H.264 encoder) looks better at the same bit-rates compared to iTunes HD films. And don't forget the audio quality. 384Kbps AC-3 doesn't cut it any more when DVDs use 448Kbps AC3 and 768Kbps and 1.5Mbps DTS, while blu-ray discs tend to have lossless Dolby True HD or DTS Master HD or just uncompressed PCM.