Location Aware WiFi Settings

This post refers to macworld.com

Lex Friedman with an iOS 6 wish list:

Some iPhone competitors offer a clever feature for conserving battery life: They use geolocation to figure out where you are, automatically enabling and disabling the Wi-Fi antenna when you’re away from a known hotspot.

This is awesome. I don’t really love location-aware features, but this could change that for me. What I am unsure about though, is having geolocation turned on that much less battery-intensive than having WiFi turned on?