GCC 4.4 has a number of benefits over GCC 4.3 in all areas. One of the GCC 4.4 features that excite us is the merging of the Graphite framework, which will ultimately provide automatic parallelization support. Also on the multi-threaded front, GCC 4.4 supports version 3.0 of OpenMP. While still experimental, in this GNU Compiler Collection update there is also better support for the C++0x language.
More on the GCC changes that are present in the 4.4 series, head on over to Gnu.org. The short release announcement for GCC 4.4.0 RC1 can be read on the GCC mailing list. The official release of GCC 4.4.0 is expected soon.