Google has added a Wifi hotspot database to cell-tower triangulation for greater coverage and accuracy. This means that Google’s MyLocation capability will be better and more accurate but anyone (site developer/publisher) using the the Geolocation API (via Gears) also gets the benefit too.
According to the Google Code Blog:
When we originally proposed the Gears Geolocation API our goal was to make it easy for developers to deliver location enabled web sites on mobile phones. However we realized laptop users would benefit from location enabled web sites too. Today we are adding WiFi signals to the Geolocation API so that laptop users can benefit from location enabled web sites for the first time and mobile users from the increased accuracy. And because the Geolocation API is the same for developers in both desktop and mobile browsers you can even use the same code on both platforms!
In Chrome and Android, with Gears built in, you can deliver a location enabled web site without requiring your users to install a plug-in, but in other browsers they will need to go through a simple plug-in install process. We also submitted a simplified version of the Geolocation API as a WC3 specification and the upcoming Firefox 3.1 plans to support the W3C version directly. The Gears Geolocation API is completely free to developers and users through the default Google location provider.
Firefox 3.1 has location (from Skyhook Wireless) and Chrome will too. Right now the Geolocation API requires end users to have Google Gears installed to work.