While Fedora 9 debuted encrypted fileystem support, F10 builds on that and fixes a number of problems that could have resulted in data corruption.
Fedora 9 debuted a preview of ext4 support. F10 brings a fully ext4-compatible e2fsprogs. In addition Anaconda's partition screen has an ext4 filesystem option available if you launch the installer with the ext4 option. Fedora 10 also brings delayed allocation for ext4. However, ext4 in Fedora 10 doesn't currently support filesystems larger than 16 terabytes.
XFS is now a supported filesystem and an option with the the partitioning screen of Anaconda