This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
There doesn't seem to be a good reason for prohibiting C language linkage for function templates with internal linkage, and that could be useful in implementations where the calling convention of a function is determined by its language linkage.
Rationale (August, 2011):
The specification is as desired.