I'd like to propose that we remove "Mahout MapReduce" and "MapReduce" Basics from the mahout.apache.org nav bar, Keeping all content either hidden so that all current blog links remain intact, or under e.g.: a "Hadoop-Legacy" tab.
I believe (and have had some feedback on this) that many people find this very confusiong. As well, Our transition away from Hadoop MapReduce to the engine neutral platform is complete. I personally prefer something like "Hadoop-Legacy" --andy