Block-based languages offer notable advantages for bringing domain-specific languages (DSLs) closer to an end-user programming audience. Nevertheless, the construction of block-based languages is still a rather ad hoc and low-level endeavour. Language workbenches [1] have been shown to be effective in improving productivity when developing tex- tual or otherwise graphical DSLs. In this paper, we sketch open challenges and work in progress to provide language workbench support for block-based languages. In particular we address dedicated meta languages for defining the syntax of block-based languages. Making block-based lan- guage development part of the common language workbench repertoire will improve the adoption of the block metaphor outside the realm of programming education, and bring DSLs closer to end-user programming.