Rather than needing to install a current FreeBSD release and then upgrade to the "-CURRENT" packages from there, a FreeBSD developer has finally started offering snapshot images of the FreeBSD 10-CURRENT and 9-STABLE versions. Yes, finally ISO snapshots to make it easier to try out the current development state from a clean install.
The FreeBSD 9-STABLE and FreeBSD 10-CURRENT ISO snapshots are currently offered in i386 and AMD64 flavors. The latest snapshots can be found here. The announcement was made to one of the project's mailing lists.
FreeBSD 10 is set to have many new features with one of the major changes being using LLVM/Clang as the default compiler to deprecate GCC. In the FreeBSD 9 world, FreeBSD 9.1 is imminent while no formal release schedule has yet to come for FreeBSD 10.0.