Fusion-io is something of a contradiction. If it's so hot why isn't it making bucketloads of cash? That's the question that comes to mind after hearing hot server flash product market Fusion-io reported a loss of almost $5m in its third fiscal 2012 quarter. Fusion revenues were a record $94.2m – 40 per cent more than a year ago …
Cause it's crap
It's not worth the cost and delivers the same performance as a SAN. They're up to a just over a gig (iirc) and can only be used in RAID 0 or 1. In a database setting you'll still need to replicate your db to a DR site which means you have to go back to mirroring or log shipping which is far more intrusive on the server than SAN replication.
p.s. Yes I do regret putting tempdb on a couple of these.