Google To Offer Navigation Offline?

According to reports from All About Phones--a Dutch tech site--Google is planning to launch an offline version of the Google Maps Navigation service allowing users to take advantage of the application without mobile broadband connection.
Though the technology has been introduced late last year, this new implementation would bring a full-fledge offline experience as early as this summer according to All About Phones's "informed source."
From Engadget.com:
In December the Android app received an update that cached routes and the surrounding areas, but without a data connection you still couldn't enter a new destination.
If true, this news does not bode too well with competing mobile platforms like Windows Phone 7 and iOS considering turn-by-turn navigation comes at a premium--offline option unheard of.
Also likely to be affect by this move are consumer GPS navigation companies like TomTom and Garmin. Will standalone GPS companies make a stronger push into the mobile market?