Intel SDE is an user-level functional emulator for new instructions.
It is built upon the Pin dynamic binary instrumentation
system. Versions of SDE are available for Windows and Linux.
The Intel "What-if" web site is here:
http://www.intel.com/software/sde/
The release notes are here:
http://software.intel.com/en-us/articles/intel-software-development-emulator-release-notes/