These are kinda ergonomic decisions, though, and a whole new language really isn't necessary for that. You could do that by making a fantastic library for another language/languages.
I'd point to PyQT as an example. It's function and documentation are flawless. I was able to build an entire web browser using it in a day(no, not a chrome competitor, just a simple one using QT and webkit components). The 'official' libraries are so clumsy in comparison.
My argument is exactly about the ergonomics. If the goal is to target Gnome in particular and take advantage of C interoperability (ideally, without the overhead of a foreign function interface), Vala seems like a solidly ergonomic solution to that problem.
I'd point to PyQT as an example. It's function and documentation are flawless. I was able to build an entire web browser using it in a day(no, not a chrome competitor, just a simple one using QT and webkit components). The 'official' libraries are so clumsy in comparison.