<p>What's better for DSL: TCL or Lisp? 
What can you say about Java(C#)-TCL binding versus Lisp(Scheme)?
What DSL tool is applicable for .Net development? (excepting Microsoft DSL tools)</p>

It really depends on who will use the DSL.
If you are expecting non-IT domain experts then something simple and straightforward like TCL would be recommended. Explaining the joys of LISP to a non IT graduate would be a serious problem as would debugging a large LISP program written by someone who hasnt grokked LISP.
Equally expaining to someone that b = a + 1 is written B = INCR(A) isnt such a good idea either.
I would recommend Python, you can embed the domain specific code in one or two specialist classes. You have a language where non-IT users can code simple readable programs, and, where there are no limits on what an IT specialist can code.