We've written about the Slingbox in the past. If you're not aware of what Sling does, it is a network device that streams live TV from your television (or Tivo, or DVR) to a number of different devices including PDAs, PCs, and soon Macs. This video shows off the Sling Player for OS X running on a MacBook.
This thing is so cool that I'll forgive the Sling guy for calling the Dock a 'taskbar.'
Oh, and the public beta for Mac should be available at the end of October/start of November.