I’m playing around with Exchange 2010 and integration with OCS for the lab and found out that the UM language packs in which MS expect to support Voice Mail Preview in the initial release is:
1. English (US)
2. English (Canada)
No Swedish as of now but there is a language pack for Swedish and all the features that only worked in English in the 2007 release now works, so at least we can control UM with voice now.