I really hope to see Go and Rust move in the direction of pluggable runtimes that can be embedded into a C host program. Currently, both runtimes require being seated as the main entry-point of the program to function. Both projects also have issues in their bug trackers to rectify this:
Also, a way to compile without kernel (system) calls, so that it can be use for kernel development. It used to be possible with go, but no more with go1. Then these languages would truly be able to replace C.
Rust issue: https://github.com/mozilla/rust/issues/3608
Go issue: http://code.google.com/p/go/issues/detail?id=2790
I wonder who will get there first.