If you wrote a specialized VM's for Python, Perl, Smalltalk, Ruby, and JavaScript on the x86 would they have any components that were largely identical?
I would postulate that there are features of a VM that are common, like garbage collection.
It would be worthwhile to work out the features common to many VM implementations and put them in hardware. Until that happens, sharing some of a VM implementation seems useful.
I'd be willing to bet that most general purpose languages that are in mainstream use could easily share the majority of their compiler/interpreter code. The main differences are in which combination of features are included and the syntax that you use.
Why put them in hardware? That sounds like an awful lot of extra silicon for every single architecture. Wouldn't it be better to have a higher level software abstraction like Parrot that you just build everything else on top of?
I would postulate that there are features of a VM that are common, like garbage collection.
It would be worthwhile to work out the features common to many VM implementations and put them in hardware. Until that happens, sharing some of a VM implementation seems useful.