In order for this to happen, it would be either very limited or very expensive. The most common presentation documents are Powerpoint (.ppd) and Flash (.swf), so any integrated projector would need to support both these file formats. But, then there are other presentation formats, such as movies. Movies are a whole other angle on this. There are so many movie formats (AVI, MPEG, MOV, WMV) and they would all have to be supported. And then you get into matters of storage...in the end it becomes counterproductive for companies to do this.
In short, tell him to get a tablet PC. As previously stated, they'll look like touch-screen remotes if conspicuousness is a concern. Or, wire the laptop through the wall, to the projector, and use a wireless pointer-clicker thing.