WebOffice 10 R3 support rotated data frames for e.g. plant information systems (plant plan often do not have north orientation).
Dataframe rotation is specified in the Dataframe properties of the ArcMap document.

Dataframe rotation configuration in ArcMap
Note: If one of the data frames of the Map collection uses rotation then all other data frames must use the same rotation as well.
Note: ArcGIS 10 SP2 does not support caching of rotated data frames.