How do I open Apple Maps from a Google Maps link in Safari?
I'm assuming you're referring to the ReMap Safari extension? Unfortunately, I'm not aware of any existing bookmarklet solution that takes a location highlighted in maps.google.com and opens it in OS X/iOS Maps (nor were my attempts at finding something fruitful). 

It's an interesting idea and I'm guessing possibly feasible given that a given location's coordinates are in the maps.google.com URL - if I was up on Javascript, I'd take a crack at it. I'll be interested to see if a solution does pop up!