Exemplifying the danger of a centralized system such as Opera Mini and also Skyfire, the browser service has just gone down after a power issue in their data centre.
The service, which is currently not reachable via the browser, uses virtualized Mozilla-based browsers to support full internet browsing, including flash video, on Windows Mobile and Nokia phones. This means when there is no connection to the data centre, there is no browsing either.
Skyfire is in the process of recovering, and hope to be fully operational soon.
Most other browsers on the Windows Mobile platform, such as Opera Mobile, uses local rendering, and are immune from the particular issue.