XDA member mike1986 and recognized developer on the forums, announced today the very first HTC Sensation ROM capable of full dual-core support.
Basically, this means that you will take full advantage of the new processor giving you more scrolling smoothness and a bit more speed when you are multi tasking on your Sensation phone. The CPU is automatically over-clocked up to 1.83GHz instead the 1.29GHz that comes by default and last but not least, the ROM is Android 2.3.4 Gingerbread from the official HTC RUU 1.45.401.2, which includes HTC Sense 3.0 UI.
Mike mentions that the Andreno200 has improved configuration for a better quality and performance.
source XDA Forums