For those who're interested - I've got the latest stable Redis 2.8.4 (http://redis.io) package compiled for Galileo.
The recipe has been added to my Galileo layer (http://github.com/alext-mkrs/meta-alext-galileo) for those of you who want to build it yourself.
The detailed instructions are pretty much the same as for node.js, so see this HowTo: How to update node.js in the SD card image to the latest release
I've got a couple of ideas on how to create a publicly accessible repo with packages for Galileo for those who don't want to compile the stuff and will look into that over the weekend. In the meanwhile I'm attaching the package to this post, you can install it according to instructions in that same HowTo referenced above.