It sounds "reasonable", but no compiler in existence seems to be able to do it efficiently. This suggests to me that it isn't in fact reasonable, as that sounds like a more reasonable conclusion than "everyone writing compilers is incompetent".
But in python, the vector operations are normally programmed using simple array semantics. For example in NumPy:
>>> a = array( [2,3,4] )
>>> b = array( [2,3,4] )
>>> a+b
[4,6,8]
It's matter of time before PyPy's new NumPy implementation take traction and make simply beautiful optimizing JITs using that.
I see this as being similar to why we're only now taking abstractions and compilers geared towards parallelism seriously for mainstream programming: not enough people needed it to justify the effort required.