A 500 gig SSD currently costs around $800. I can't imagine the price of solid state storage dropping low enough to compete with an optical drive and inexpensive blank media. Of course, the unknown variable here is the cost of holographic blank media. Blank, 25 gig, Blu-ray disks cost around a dollar a piece.
Personally, though, I would love SSD to become the default bulk storage medium technology. When my hard drive failed last winter, I upgraded to Win 7 and an SSD, and I love how quickly stuff loads up off the SSD. I use a 1TB eSata drive for bulk storage, and it's annoying when I have to wait for it to spool up.