Longevity
To answer the question of longevity, it depends on a variety of factors including the number of disks used, how the drives achieve wear-leveling, temperature, and, of course, the disk technology. SLC flash is said to endure up to 100,000 writes, whereas MLC flash is said to endure up to 10,000 writes.
For those who (like myself) don't really know too much, Super Talent has a good white paper on SLC vs MLC:
http://www.supertalent.com/datasheets/SLC_vs_MLC%20whitepaper.pdf
EDN has an article on SLC vs MLC ("http://www.edn.com/article-partner/CA6319917.html") which tries to make 10,000 writes sound like a lot by saying "a USB drive application that used the 10,000 write/erase cycles would enable the user to completely write and erase the entire contents once per day for 27 years, well beyond the life of the hardware." Of course, most systems will write to a drive more than once per day. Imagine how many times your OS writes to its swap file. And keep in mind that as free space decreases, so does the effect/benefit of wear-leveling.
Also, don't believe the BS from this press release. First, they claim that a comparable HDD-based solution would cost over half a million, but then they conveniently fail to mention how much their kit is going to cost. They also massively inflate the number of HDDs which would be needed, and even more so the power required (they're obviously completely ignoring 2.5" HDDs which run at about 1/4 the power of 3.5" drives). Don't get me wrong, I'm sure this array has legitimate uses which will be worth the cost, and it IS an impressive array. But I can't stand it when a company compares their new technology to the worst contenders of an old technology just to make their product sound better. If your product is so good, then it should stand out on its own merits.