Those are great questions and thanks for your interest in the Slingbox 500. There are plenty of cool new features with the 500 that aren't available with the PRO-HD. Independent viewing is not one of them, the Slingbox is not a stand alone cable box and you would still need a dual tuning cable box in order to view independently from a viewer at home on the same cable box. The 500 does have WiFi capabilities and a host of new features including My Media, a physical remote for OnScreen TV Setup and more.
Here are a couple of links form our product and support pages with some additional information on the features of the Slingbox 500:
Hope this answers your inquiry!
The Sling Moderation Team