FreeBSD 10.0 RC2 fixes multiple Radeon KMS driver bugs in its ported code from the Linux kernel, wireless bug-fixes, and Clang compiler bug-fixes. There's also a fix for a bsdinstall regression when installing ZFS on GELI, and some iSCSI disk improvements.
More details on FreeBSD 10.0 RC2 can be found via the FreeBSD-stable mailing list.
Prior to FreeBSD 10.0 final is still a third release candidate, which is likely to come in about one week's time. After that, there's no other planned development releases prior to the official release. The FreeBSD release engineering team right now hopes to FreeBSD 10.0 on the 2nd of January. Details can be found on their 10.0R schedule. FreeBSD 10.0 brings many new features but has been plagued by multiple delays.