OS X Consumer Rumors
MacOS Rumors reports "At present, Apple's plan is to include the complete BSD UNIX layer in the Server version of Mac OS X, but not in Consumer; Consumer will have only the bare-essential components, and no Terminal or Telnet access to a command line. However, a complete BSD installation has long been rumored as optional for Consumer, and even if Apple chooses to leave it completely out of Consumer's installer, it won't take long for a simple Darwin install to be developed to work within Consumer. "
I suppose that security concerns could be behind this reasoning -- but part of the appeal of Mac OS X was that you could drop down to a command line shell. There's "hide" and then there's "remove" the internals.