I expect my PDA/MID/device to support such switching between private and business usage by simple selection of profimes, NOT by having to carry OHs with me. I bet I always don't have the "private OH" at home when I want to call my friends from office to plan the evening. And when in the evening I'm with my friends, I miss the "office OH" to call a colleague about that detailthat just occurred to me should get sorted immediately. Ultimate information security is achieved by proper encryption, not by leaving unencrypted "pluggable storage" at home where any burglar can take it away. The argument about uSD vs OH is like suggesting to go back to Sony Walkman and Phillips cassette since then you don't need to carry your complete album collection with you and cassette is way less prone to lose than any more contemporary storage medium.
Jollas concept is nevertheless revolutionary - customizing the device: landscape qwerty...