Big box retailer and DVD sales powerhouse Wal-Mart is scaling up its movie and video download service by offering a fully active public beta of the online store. The service initially launched as a limited beta in November with the DVD release of Superman Returns and a special offer for a downloadable version of the movie.

Forbes reports that Wal-Mart's movie library includes about 3,000 offerings from all the major studios as well as some TV networks. ABC, NBC, and CBS, however, have not signed on. In comparison, Apple's iTunes Store offers movies only from Disney and Paramount, but includes TV shows from wider range of networks.

Wal-Mart's movies will be priced ranging from US$12.88 up to $19.88, and TV shows will cost $1.96 each. Movies from iTunes cost $12.99 when pre-ordered, and during the fist week of sales. After that, they jump up to $14.99. TV shows are priced at $1.99 - four cents more than Wal-Mart.

Movies and TV shows will be encoded with Microsoft's PlaysForSure DRM, which limits playback to Windows-only PCs and compatible portable media players. The copy protection prohibits playback on Macs, the iPod, and Microsoft's Zune.

Although Wal-Mart's movie service blocks out the most popular media player, it may ultimately allow for more content to make it to the iTunes store and then onto your iPod. Studios that may have been hesitant to sign deals with Apple for fear of upsetting Wal-Mart, the single largest reseller of DVD movies, are now in a better position to feel comfortable about bringing their films to the iPod.