No, I'd say that RAID is still necessary. RAID and solid state complement each other. There's a notion that RAID is just for disk drives, and that's not the case. One solid-state vendor, Texas Memory Systems, recently released a solid-state storage system that combines traditional RAM cache with multiple flash-based modules, with the flash modules actually configured with RAID 5 for availability and read performance using the read cache to offset the RAID 5 penalty. This is a great example of a hybrid systems, as well as hybrid drives, complementing each other with the RAID for availability and performance.
Even some general purpose x86 class servers have been shipping for several years now with mirrored RAID -- RAID 1 for availability and redundancy purposes. It's a good fit across different technologies, and it's not just for disk drives anymore.
Check out the entire RAID FAQ guide.
This was first published in November 2007