Are you aware that there is a version of DB2 that you can use free of charge? It is called DB2 Express-C and it is basically IBM's way of removing price as being the issue in terms of you trying out and using DB2. Think of it as a way to use DB2 just like you would use an open source DBMS (except you don't get the source code).
According to IBM: DB2 Express-C is a version of DB2 Express Edition (DB2 Express) for the community. DB2 Express-C is a no-charge data server for use in development and deployment of applications including: XML, C/C++, Java, .NET, PHP, and more. DB2 Express-C can be run on up to 2 dual-core CPU servers, with up to 4 GB of memory, any storage system setup and with no restrictions on database size or any other artificial restrictions.
So, if you are wondering what it means for DB2 to support pureXML, then you might want to download DB2 Express-C and try it out for yourself. DB2 Express-C can run on AIx, HP-UX, Linux, Solaris, and Windows.
Now why would I be writing about a LUW product on a z/OS blog? Well, DB2 9 for LUW and DB2 9 for z/OS both support pureXML in the same way. So even if you are a DB2 for z/OS user, getting familiar with the XML support in DB2 Express-C can prepare you to help plan for how you might want to use XML in DB2 9 for z/OS when it becomes available.