I would dearly love to see a full-blown Modula-3 revival. It's one of these old, moribund languages that I have a huge soft spot for, especially since I'm a Pythonista and large parts of Python were lifted directly from Modula-3.
I also kind of have a thing for innovative languages that never really took off. Not just M3, but I'm also deeply fascinated by Algol 68.