Boxee TV/cable question

Question I'm hoping someone can answer for me... if I just plug in my existing cable line into a new Boxee TV box, will I get the same channels I have now with my cable box just in the slick new interface and the ability to record to the cloud/playback on other devices? Or will I not have access to premium content (ESPN, CNN, etc.)? Also, does anyone know if you can watch live TV on your various devices via Boxee TV or is it just playback of previously recorded content?