does anybody know how to download the officially released rom from Samsung? I can't see it in the web site and kies does not donwload anything, currently I am using the 2.3.4 updated a while ago. I have the phone in Switzerland (Zurich) and my Phone operator is Sunrise. Thanks!
Samsung's Kies software is the official way to download and install updates. These updates are released on different dates for different countries and networks and some countries/networks don't have all updates. It may be that your network hasn't tested and certified the update yet, or they might not be releasing this version at all.
This page lists most of the official updates available via Kies for the Galaxy S2 I9100 phone: