Remember that proof-of-concept you saw way back in June of last year? You know, that one involving SlingPlayer Mobile for iPhone? Here at Macworld, Sling Media is doing its darnedest to take the spotlight away from the looming Apple keynote by announcing that said app is almost ready for consumption. It'll be demonstrating a functional version in San Francisco, and it's planning to submit the software to Apple for certification sometime this quarter. In case you couldn't care less, it'll also unveil a prototype SlingPlayer for Mac HD, which will enable Mac-using Slingbox PRO-HD owners to stream high-def material to their Mac. As for the good stuff, pricing has yet to be determined for the SlingPlayer iPhone app, but the SlingPlayer for Mac HD will be made available gratis.