I think Samsung might be doing themselves a disservice by not releasing JB on the Galaxy Tab 10.1. Android, and in particular Samsung have a reputation of having infrequent update cycles and short support periods. iOS and iDevices (and Nexus devices for that matter) are much more likely to have frequent updates with longer support periods.
Most of us would agree that this is a disadvantage of the Galaxy Tab series and that about 1 year after release you can bet that it will no longer receive upgrades. Any potential buyer of a Samsung device doing some basic research may approach these or other forums to get some advice from the 'experts' and count this as a point against buying a Galaxy Tab.