Oh, I'm not doubting it'll happen. It just won't happen in time to supplant Blu-Ray and/or HD-DVD.
And doesn't flash memory have a limited number of read-write cycles? Not very useful for long-term storage and usage.
Long-term offline storage? It'll lay there in the protective envelope a long while. Long-term usage? Here's a page...
http://www.bitmicro.com/press_resources_flash_ssd.php
"Unlike DRAM, flash memory chips have a limited lifespan. Further, different flash chips have a different number of write cycles before errors start to occur. Flash chips with 300,000 write cycles are common, and currently the best flash chips are rated at 1,000,000 write cycles per block (with 8,000 blocks per chip). Now, just because a flash chip has a given write cycle rating, it doesn't mean that the chip will self-destruct as soon as that threshold is reached. It means that a flash chip with a 1 million Erase/Write endurance threshold limit will have only 0.02 percent of the sample population turn into a bad block when the write threshold is reached for that block... With usage patterns of writing gigabytes per day, each flash-based SSD should last hundreds of years, depending on capacity. If it has a DRAM cache, it'll last even longer."
I'd say that compares more than favorably with the CDRW format. For offline storage and archiving, we should use optical, mainly because there aren't enough cliff-faces on Earth to hold the information we all store, and we'd wear out our hammers and chisels (and spend our lives) trying to record it all.
The nice thing about format wars is, if one keeps in mind that all victories are pyrrhic, one can wait just a little while and save money, if one shops carefully. Zip disks were a handy format, but lost their appeal with faster, larger, cheaper hard drives and then along came CD burners. Zip is still available -- Iomega's other forays into similar but not quite compatible media formats haven't been resounding successes, mainly because the cost of media never came down enough.
DVDs are cheaper to make than CDs -- unless the higher price per MB for commercial titles on CD vs DVD is just a sign that there's way too much financial burden from cocaine in the music industry. ;') An album recorded 20 years ago and available on CD is often more money than a DVD version of a movie from three years ago.
Blu-Ray vs HD-DVD:
http://www.pcworld.com/news/article/0,aid,119665,00.asp