For Mojo, I'm interested in seeing how the language can be used as a path forward for the Cython community. This could be a stepping-stone towards reimplementation of Python in Mojo. For the past 3 year, I have been talking about the need for a Python-Steering-Council-recommended extension language for Python. This will be particularly important as WebAssembly keeps progressing and potentially redefining what we mean by virtualization and containers.
We have already been using LLVM extensively in Numba and there have been several explorations around MLIR and related technologies. There are several potential paths forward and I'm looking forward to finding ways to cooperate.
Understanding what will be open-source is of course, critical for that.