MySQL for AS/400

I just found at golem.de (German it news site) that MySQL will be available for AS/400 with DB2/400 as a backend (yes, I still call it AS/400 whatever IBM marketing will come up with: iSeries, i5, System i or what it is called now).
My first thought was that this got to be a late april's fools day joke - why would anyone want to use MySQL on a AS/400 as DB2/400 is an integral part of the operating system.
Ok, after looking at the announcements from IBM and MySQL it seems this was mostly done to make thousands of open source MySQL and PHP applications run on AS/400. Oh well ... database abstraction anyone?