I use it in little ways, here and there. Its syntax inspires any tool-command syntax I write (see http://yosefk.com/blog/i-cant-believe-im-praising-tcl.html). I have a few Tk scripts around to launch tasks (generate a new data repo, run various forms of regression tests, etc.); nothing beats Tcl+Tk for "build your own tool" GUIs. When experimenting with C code, it's useful to just embed a Tcl interpreter to run bits of it. Sure, I could use Lua, but Tcl's even easier.

None of those are legacy projects, but none of them are the primary focus of my work, either.