Agreed on that. Plus, i noticed a mistake made by a lot of people, Redis is NOT memcached. That's just as easy as that. You can use Redis the same way as you would use memcached, but that would be a waste.
The power of Redis resides in its data structures and the usage you make of it. You can make some pretty powerful stuff, easily and with performance.
Nested Comment system (https://gist.github.com/803251), autocomplete (http://pastebin.com/E5h1TLWz), all of that with high performance over large dataset, and much more, stuff that is not doable with Memcached. Also, the role of Redis is not to replace SQL databases, i personally view it, and use it, as a complement to it, and it works just perfectly. (I am fully aware that the examples given are possible with SQL solution, but experience in production/development as shown me that Redis is easier and faster when it comes to not too complex operations like these ones)
