I think the removal of HDMI and the SD card slot, together with the switch to USB-C only will make this machine very annoying to use until every device in the world transitions to USB-C, including projectors, TVs, peripherals, etc... That's going to take years. Until then, don't forget your:
- USB-C SD card reader that you probably don't have yet
- USB-C to HDMI or VGA adapter for when you need to use a projector for a presentation or a TV for video editing
- USB-C to regular USB adapter for, let's face it, everything
- USB-C to Thunderbolt adapter for if you use an external monitor
Personally I really hate adapters, and I hate paying money for them and having to bring them everywhere I go because who knows when I'll need them. Nothing's more comfortable than plugging in my Mac directly to my HDMI TV for video editing, or putting an SD card slot in it when downloading photos during a shoot. I've never had to use an adapter with my current rMBP. I remember when the only video port on the older machines was the Mini DisplayPort which was and still is incompatible with everything, so I always had to have the adapter with me.
Having 4 USB ports would be great, except 1 will be occupied by your charger, and 1 by something that was built into previous computers (SD card slot, an adapter for HDMI or Thunderbolt or VGA, etc) so you'll just end up with pretty much 1-2 free USB ports, which is as good as or worse than what we have now.