Other thoughts on Oracle

Dalvik was born without a JIT, and Ruby is getting some performance work.
If you mean for a fast switch, these scripting languages (except Lua) have abysmal performance - I refer specifically to Python and Ruby - and I'm perfectly aware of PyPy, Unladen Swallow, JRuby.

However, Google has enough engineers to reimplement a VM for another language again, like done for Dalvik.

And people (up to Miguel de Icaza) suggested that .NET was safer: http://tirania.org/blog/archive/2010/Aug-13.html