According to several unnamed and unofficial sources, Amazon will soon add HD content via their Video On Demand store, though it seems that this will be offered on TiVo set-top boxes only. The unofficial sources also say the progressive downloads include surround sound information for a Blu-ray HD movie-like viewing experience. Last week, Amazon began offering its VOD library via the Roku Player, though no HD content is available. Mention of HD Amazon videos on TiVo has been kicking around since last year, when unused shortcuts to HD content in the TiVo menu were discovered.

Exactly when or how much the HD service on TiVo will launch is not known. [via ZatzNotFunny]