Subscribers of HBO's On Demand services will soon be able to get video downloads of their favorite shows and movies online, free of charge. That is, if they run Windows, live in Wisconsin, and use Time Warner Cable. HBO announced today that the service would launch this week—initially in Wisconsin and eventually expanding out—to an increasingly crowded video download market. With HBO on Broadband, the content provider hopes to keep the customers it might have previously lost to other services (such as Netflix) by offering them a wide selection of content with a decent level of flexibility. But HBO could be getting ahead of itself by launching this now, because its parent company, Time Warner, has other plans for customers' bandwidth.

First the nitty gritty: HBO on Broadband will offer over 600 of HBO's shows and movies for unlimited download to HBO On Demand subscribers. Users can download and watch videos as often as they like for no additional charge, a representative from parent company Time Warner wrote on DVD Dossier this morning.

Using a proprietary media player from HBO, users can also authorize up to five computers on a single account, but they must be using Windows Vista or XP SP2 in order to make use of the service. (Predictably, the company says that a Mac version is in the works, "but no release date has yet been announced.") Content will constantly be rotated in and out so that there are new selections to watch, and users will even be able to watch a live stream of the east coast HBO feed at the same time it's being broadcast on TV.

There will, however, be some level of DRM. While users will be able to take files with them on a laptop, they can't be transferred to other portable devices (like iPods and Zunes), and won't remain watchable forever. "Individual titles will be available on the service for 4-12 weeks, with episodes of HBO original series generally available for longer periods than theatrical films," reads the DVD Dossier post. "When a title reaches its 'expiration date,' it will automatically be deleted from your computer."

Despite its limitations, HBO on Broadband doesn't sound too shabby. But it seems a little odd that HBO is introducing this service now. Why? Time Warner is planning to start rolling out bandwidth caps on its broadband services this year. This means that some of Time Warner's own customers won't be able to make full use of HBO on Broadband—at least not without paying for a higher tier of service.

It seems that one of two things is happening here: either the right hand doesn't know what the left hand is doing, or this is all part of Time Warner's plan to milk more money out of subscribers. For now, Time Warner only plans to test the bandwidth caps in Texas, while HBO plans to introduce HBO on Broadband in Wisconsin, so the services won't cross paths just yet. But when they do, customers aren't likely to be happy to find out that their "free" online services from HBO are eating up their bandwidth quotas elsewhere.