Is there any reason not to run Asterisk on an Intel Atom board?
Only if it’s not strong enough. Note that “Atom” may mean some different
things. So consider taking various reports with a few grains of salt.
Like Tzafrir says keep an eye out for what “Atom” is. The 1.6-1.8 ghz
processor is powerful enough for simple servers but some of the
supporting chipsets and hardware may not be. My personal suggestion
is the http://www.supermicro.com/products/motherboard/ATOM/ICH9/X7SPE-HF-D525.cfm
which also has an IPMI onboard.