A big thanks goes to jan-jaap on the Nekochan Forums for pointing out you can, if you're only doing non-commercial development. This license applies to x86 and AMD64 as well.

First, go to Intel's site to register an account (it doesn't work in IE 11 at least in the Windows 8.1 Preview).

Second, you'll receive an email with your license key, be sure to keep this handy as the installation requires it to activate.

After clicking the download button in the email, then click Additional downloads, updates and versions.:
Intel Cpp Suite
And then select Intel C++/Fortran Compiler 11.1 Update 9. As of this writing the file is l_cproc_p_11.1.080_ia64.tgz.

After downloading it, extract it and run the install.sh:
[shell] tar -zxvf l_cproc_p_11.1.080_ia64.tgz ./install.sh [/shell] The install process is pretty trivial - afterwards you'll have access to the Intel C++ compiler installed to /opt/intel/Compiler/11.1/080/bin/ia64 (assuming you installed it to the default folder).

To compile with the Intel Compiler just call icc. At this point it would make sense to add the Intel Compiler to your PATH.

Hope it helps someone out - I would highly suggest if you have any inclination of doing ia64 development, to get it downloaded now before it becomes unavailable at some point.