First off, I apologize for my thoughts being all over the place at 3AM in the morning ;)
I've written several transactional systems using Oracle and DB2 in the financial industry in a former life. The trappings of SQL are directly proportional to it's power. As demonstrated in mysql-sr-lib they can be packaged neatly to great effect however. Also I was talking about transactional operations on datasets.
Lastly, on slowness of SQL. I just meant that query plans cost and are not free. There have been several experiments of late of the amazing performance you can get by working with InnoDB directly instead of going through MySQL for example. Basho is just one of the players that has done work in the space. There is also hook that can be directly embedded in MySQL to bypass the standard workflow and interact directly with the datastore.
My main point in all this is that it will take some time to reach a 1.0 version of a viable, modern persistence solution in Redis. Time would be better spent now at least evaluating other open source persistent engines before diving head first into a very shallow pool. The main point is that most of the current persistence tools have been battle tested in a number of environments, antirez should leverage that considering the small size of his team; just two people.