Uniform / easier PC's
PCs would be a lot easier for a lot of people if there were only one type of connection - for everything.
ps/2 ports for keyboard and mouse are all but obsolete, pretty much any new k/b or mouse uses usb. but we still have, for example, cat-5e ports. why not make network cables use USB ends?
that still leaves a few more things that could be converted - at least once we get the new usb 3.0 spec.
SATA? Why? Just replace it with USB. Put USB ports inside the computer.
PCIe? Replace it with USB. Provide sufficient means for cards to dock inside the computer. In fact, strategically place the USB port inside the dock so we don't have to use wires. This could be done with internal drives, too.
That pretty much leaves just HDMI, VGA, and DVI output. VGA is analog but totally obsolete. There's no reason to use VGA anymore. In fact it's a travesty unless you have a CRT. HDMI is a bit outside our domain of consideration because it's an interface to a non-computer device; you can't control that, there are too many non-computer devices out there. DVI, on the other hand, could be usurped by USB. Let's see.. usb 3.0 will be 3.2 gbit/s after protocol overhead, one pixel is 24 bits, that's a possible 64 frames per second at 1920x1080 resolution. Well, I guess it just barely cuts it in that department. We can always sell new monitors with USB connectors that require up to 3.2 gbit/s, and after that use dvi... until we get USB 4.0
Wouldn't it be awesome if there all computers had exactly one type of port and came with about 12 of them?