sling media is one of the companies 'rumored' to have an early version of the SDK - even if they haven't received it early, i am sure they will develop a slingplayer for the device(s) ... iphone/touches are gaining too much popularity to ignore. unfortunately, i'm 99.9% certain it will carry a price tag in the $20-30 range... as slingplayer mobile runs
$29
as for 3rd party... i think only sling media is able to develop a player for their devices, so you will probably be stuck buying the full app from them/itunes.