I am just shooting an idea.
Is it possible to have DSL staging where for a DSL you auto generate an optimising AST interpreter in a base language. If this is taken further the translation can be to another base language and in case low level base languages are supported this would become JIT.
Any way I think it would be good to have some form of staging support in your product.
P.S. MPS has the potential to be a great tool for both DSLs and GPLs covering 360 degrees of the PLT. Please aim for the true potential. Get internal and external support to go beyond what you are currently targeting and sell this idea to all stakeholders. - SD