Several customers would like to use the console with the US language setting, even though the client OS is of a different language. In both SCSM2010 and SCSM2012 the console will start up the same language as the client, but for SCSM2012 the users now have the option to change that::
But still, the console will initially startup in the same language as the OS. So if you want to choose the language for your users, you will have to set the lanaguage code in HKCU\Software\Microsoft\System Center\2010\Service Manager\Console\User Settings.
Using a Danish OS sets the Language to da-DK and by changing the key to en-US it starts in the US language. This is very usefull if deploying the SCSM console via SCCM and you want everybody to use the same language setting. Then you also don't have to worry about the mix of language codes and display strings decribed here.
Also, if you want to help your users to connect to the rigth SCSM server, set the SDKServiceMachine while you're at it.
Remember these settings are to be set under HKCU, making it a little bit cumbersome.