I had more or less expected Blu-ray to supplant DVDs as the removable storage medium of choice in PCs, but after reading this little write-up about what Apple is doing with its MacBooks, I'm suddenly not so sure. Optical drives are awfully large and cumbersome for inclusion in smaller laptops, and Apple isn't alone in favoring SD card slots instead. Apple has, though, traditionally pushed the industry toward dropping older standards, as it famously did when it ditched floppies. (Well ahead of the appropriate time, some might say.)
Beyond the fact that SD cards are absolutely tiny compared to optical drives, optical storage is threatened by the continually plummeting cost per gigabyte of flash memory and the rise of online software distribution. Already, as this article points out, 32GB SD cards have nearly eight times the capacity of a DVD, too. Could it be that, in a few years, the standard OS installation procedure will involve booting from an SD card? Hmm. Now that you mention it, it almost seems like a matter of time.