If any updates, upgrades or other stuff will be available for your German xda, O2 - DE will offer it for download on its Mobile Portal.
I expect to see there Micrsoft's End User Upgrades (EUU) as well as GPRS stack updates soon. By the way: if any upgrades/updates are available don't make the mistake and download it wireless with your xda as some files could include 12 MB and more, doing this wireless through GPRS would makes O2 rich and you poor! ;-)
Thanks to Michael Roessner for heads up!
Cheers ~ Arne
Related Links : [More Information]