The linuxmce.com web site, under the heading "Why buy a licensed LinuxMCE product? What's the difference?", implies that there are commercial versions of Linux MCE available for purchase. However, after googling around for awhile I can't find any distributers or manufacturers of such a product.
Is anyone aware of a turn-key product based on Linux MCE that I could just purchase, plug in and be up and running within minutes?
Take a look at www.plutohome.com
to see the Pluto system - linux-mce is based on Pluto and is aimed more at commercial installers (although is also has a following of private individuals to). Another place to see someone delivering a commercial product around linux-mce is www.fiire.com
(although in this case its standard linux-mce on custom hardware).