Update: the deal is now official, with Amazon adding "thousands" of TV episodes from MTV, Comedy Central, Nickelodeon, TV Land, Spike, VH1, BET and CMT to its Prime Instant Video service.
Amazon's Prime Instant Video is currently a part of the Amazon Prime program, which provides members with unlimited two-day shipping and other benefits for $79 per year.
In September, Amazon inked a video deal with Fox; previously, the company signed deals with CBS, NBC, Sony, Warner Bros. and others.
The addition of Viacom to that list is another sign that Prime Instant Video might soon become a full-fledged competitor to Netflix and other streaming video companies. Google and Verizon are also expected to launch an online video streaming service in 2012, which should make for a very interesting year.
The competition for the streaming video crown is also heating up in the UK, where Netflix recently launched its service to compete with Amazon's LoveFilm.
[via Reuters]