This is actually a significant release for Riak. Something that has always been sited as lacking in Riak was it's ability to index documents similar to couch. With this release, http://bitbucket.org/basho/riak_search/src (beta), what they have done is integrate lucene indexing on top of their distribution mechanism.
I had never heard of Riak before (shame on me!) and it looks like the exact thing I would need for a project: does anyone care share success|horror stories?
What about price? There is a free version but the prices of the commercial version (with support) are not disclosed. This makes it look like it's targeted at big companies...?
You should take ~45 minutes and go through their "Riak Fast Track." https://wiki.basho.com/display/RIAK/The+Riak+Fast+Track It's fantastic (all software should be so well documented!) and will give you a much better idea of what it can do for you.
I enjoyed working on Riak for an internship project I did but I would say that if you are not familiar with using map reduce heavily for querying that you factor that into the amount of time you are going to spend to get Riak up and running. I don't know much this Riak search will impact things but I was storing data in JSON and ended up using a lot of time debugging MR queries because I didn't quite grok some of the finer points such as idempotence.
The big company/small company thing isn't a big deal. I work for a very small company and we were able to get the free version going pretty painlessly.
I launched a service to production last week that uses riak_core to distribute load/storage to 8 nodes. Documentation is a little sparse, but I was impressed by how easy it was to take my single-node service and distribute it using riak_core. Definitely recommended.
Riak means "ripple" in Indonesian. This is both the name of a pre-release version of the software and a reference to how storage operations in the k/v store work.
Besides that big news, this release intriduces a number of performance enhancements over it's predecessor. Read all about it, http://bitbucket.org/basho/riak/src/tip/releasenotes/riak-0.....