As far as I'm aware, USB Mass Storage is still available in 4.0/4.1 (Vendor Optional), but only for external storage (MicroSD storage). For those of us with Internal storage USB Mass Storage is not an option.
It may also be possible with CM9 if they partition the Internal Storage to give the appearance of both Internal and External Storage - but it remains that only the 'external' storage is usable with USB Mass Storage.
As far as I'm aware, USB Mass Storage is still available in 4.0/4.1 (Vendor Optional), but only for external storage (MicroSD storage). For those of us with Internal storage USB Mass Storage is not an option.
It may also be possible with CM9 if they partition the Internal Storage to give the appearance of both Internal and External Storage - but it remains that only the 'external' storage is usable with USB Mass Storage.