According to today’s AP wire, NetFlix has started to accelerate its transition away from a mail-in business model. The company has begun marketing a broadband device that consumers can use to stream movies and TV programs.

And the impact on the Net? Consider a few numbers courtesy of PBS’ ever-insightful Bob Cringely:

“Just look at the comparative sizes of the QuickTime HD trailers for the upcoming Indiana Jones and the Kingdom of the Crystal Skull…. The 480p trailer (that’s standard definition and slightly better quality than the 640-by-480 shows most people download through iTunes now) requires 47 megabytes while the 720p file is 78 megabytes and the 1080p version requires 126 megabytes. [Assuming a two-hour movie] the ultimate file size for the H.264 download versions [would be] 3048 megabytes, 5059 megabytes, and 8172 megabytes, respectively.”

[Image via Flickr]

In short, each two-hour HD movie download adds 3-8 GBs to the web, depending on the display resolution. Netflix won’t be sending all its movies in HD resolution yet — but it’s only a matter of time. Now think about this practice going mass-market while Congress prohibits common-sense network management as part of Net neutrality.

This Friday evening, if you pass through the 405 in Los Angeles, the I-10 in Houston or the Circle Interchange in Chicago, look around. You’ll get a good idea of the Net’s future under Net neutrality.