I'm very glad that only game writers are using Tcl for scripting their games. It's a godawful language I'd never want to maintain any real software in. Python and Ruby are bad, but Tcl is a degenerate joke. Let's please leave it undiscovered.
Tcl is the major scripting language used by all FPGA vendors, and sadly it doesn't look like it is going away. You can call Python from it, but FPGA developers (especially those Windows) will make a big fuss about installing an external tool, and should they install Python2 or Python3? Also, the major FPGA programming languages (vhdl and verilog) make tcl look great (or any other language, for that matter).
You may be pleased to learn that game developers do not use Tcl for scripting these days and, indeed, few ever have; see http://wiki.tcl.tk/40487. Their embedded language of choice is, by a large margin, Lua.
