No its a pretty clever question and after thinking about it for a while, I didn't have a good answer.
Heavy VX= bad canidate for a 4 cylinder
I4 smaller/lighter than 3.5L= good weight shed for VX
I4 turbos= possible annoying turbo lag (maybe not since there's 2)
I4 more HP= that's all good
I4 better MPG= also all good
Sky/Solstice short production run= that engine could cost big $$$
Too many pros/cons to make a stance. I think its a great idea as long as the extra 45HP goes to the wheels. Then again the MPG alone may make the swap worth it.