I have posted SdFatBeta20110810 here http://code.google.com/p/beta-lib/downloads/list.
Here are the main changes:
Added support for multiple SD cards.
Change the name of SdFat::cwd() to SdFat::vwd() since the volume working directory is not the current working directory with multiple SD cards.
Added the static function SdBaseFile::cwd() to return a pointer to the current working directory.
Added the TwoCards.pde example to demonstrate use of multiple SD cards.
Added readCSV.pde example to demonstrate iostream extractors.
Added bool SdBaseFile::timestamp(SdBaseFile* file) to copy one file's timestamps to another file.
Improved messages in the QuickStart.pde example.
Added maximum latency test to the bench.pde example.
Rearanged class hierarchy to fix conflicts with Flash.h and other Adruino libraries. Print is no longer a private parent of file stream classes.
Added high speed multiple block read functions to Sd2Card.
Changes for Arduino 1.0.