HTML5 means no download required. Developers will able to embed code to provide navigation direct from any browser.
From the iPhone Blog:
TeleNav, one of the largest back-end providers of GPS navigation services for smartphones and other in-car turn-by-turn navigation systems, has announced the upcoming release of a free HTML5-based voice-guided GPS navigation service that works on your iPhone through the Safari Mobile Browser.
From the TeleNav Site:
The HTML5 navigation service will include full-color moving maps, audio directions, and automatic rerouting if the driver misses a turn. TeleNav’s HTML5 navigation service will be free for both developers and consumers and will support all major mobile platforms.
By simply adding one line of code, developers of mobile websites or of apps with local content will have a free and easy way to integrate full GPS turn-by-turn directions into their services, creating a more seamless user experience and increasing user engagement and time spent within their applications.
Anticipated Launch: Early 2012