Most mobile computers don’t have enough space to house or implement full-size versions of all the latest and greatest connectors. I’m talking about, instead of putting ports directly on the computer, having a dongle that includes HDMI 1.3, eSATA, USB 3.0, FireWire 3200, SAS. Okay I’m joking those standards are too new but eventually you know they’ll have them.
A problem most mobile computers have is that they get stiffed with the mini-FireWire, mini-DVI, mini-HDMI, and whatever else they can make a stupid mini version of. What sucks even worse is that these mini versions often skimp on the specifications, like they don’t carry enough power or just aren’t powered at all.
One last thing, the ports on mobile computers are usually too close too each other in the first place. So in other words, a break-out cable wouldn’t have any problems with fixed inputs being too close together.