1.1

There are very few pitfalls, none of which I see as real killers.  These include:

1.) Closed source compiler: Yes this stands against what we believe, and yes by closing their source they're protecting the trade secrets of their architecture.  It also could be more difficult to debug, although that's highly unlikely, they have the idb (intel debugger) which works very much like gdb.

2.) Linking issues: So far it's pretty versatile, but it doesn't always cooperate with gcc compiled apps.  It may be a good strategy to make the troublesome apps which won't compile with ICC compile with ICC.

Pro's:

1.) Bloody fast machine code.  Intel obfuscates their architecture but they give back to the community as much as possible to make their hardware marketable toward the open source sysadmin, developer, etc etc.  Their drivers are open and they develop for the kernel constantly.  This cooperation leads me to believe that they would assist a team of developers in making 100% icc compatible code.

2.) Bloody fast compilation time.  In my experience the compiler works much faster even with heavy optimization.

3.) Takes full advantage of SSE enabled hardware.  SIMD instructions are quite useful, code is extremely vectorized.

4.) will project gentoo toward the power user more, helps the gentoo image, and overall will make linux a more professional operating system (and a quite competitive alternative to something like a SPARC+Solaris configuration).  This would also make cluster farms and science application more respectful toward the gentoo community.  The academic and research world already uses ICC to compile their apps for the sake of speed.  The interprocedural optimizations for both the fortran and c/c++ compilers make it a must.

5.) It's free, albeit a commercial product.  As gentoo is entirely non-profit, there is no restriction when it comes to licensing.  The binaries won't be sold for the intel-compiled livecd, and the compiler itself with a fetch restriction allows the user to legally register for their free non-commercial license.  
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