It doesn't have internet yet - I think that is coming, but not in my model. I have no wifi access, although I've heard rumors that it will be released in Europe before the US. The e90post forum doesn't have much in the way of information regarding the iDrive - it is still pretty advanced. I was the first to even partition table of the drive with fdisk.
Edit after more research: Actually, these cars have cellular phones (I believe EVDO) in them which allow them to communicate with BMW Assist and also to request more CD info for new CD's not in the internal GraceNote database.
My ideas are not so much a software hack to iDrive as that is beyond my resources to reverse-engineer. I'm thinking more along the lines of a hardware hack like an alternate input to the screen and some sort of KVM-style switch for the controller.
I'm only vaguely familiar with the Sony Stalk integration, but I'm thinking that the connection to the empeg would be somthing like that. The KVM question still depends on the way the controller itself works.
For the screen, there is a LVDS connection. This may be the more difficult task - to convert the LED panel to to that format. I have seen some LVDS converters for other video formats, but my knowledge of LVDS is rather limited so far. That screen is great in the direct sunlight.
Well, I realize that most aspects of this mod are far from easy, but seeing the slowness of car companies to make a decent car Media player make me inclined to look into it.
Who knows, maybe years down the road, someone can get their hands on more information on the iDrive system and hijack it like The Lord did.