Competition between makers of settop units that allow consumers to watch online content on their television sets picked up with reports on Tuesday that Microsoft plans to offer a high-definition (720p) version of its Zune multimedia portable device on September 15. Consumers can view videos on the device itself -- Microsoft's answer to Apple's iPod -- or they can connect it to their TV sets using a docking unit (sold separately). Pricing was not disclosed. Meanwhile, Roku, which makes the $99 settop box used to stream videos from Amazon and Netflix to TV sets, announced that it has signed a deal with Major League Baseball that will allow subscribers to MLB's website to watch live games all over the country -- many of them in high definition.