If you need expansibility and are running a large external monitor, that sounds pretty 'professional' to me.
http://store.apple.com/us/product/MJ1K2AM/A/usb-c-digital-av...
and
http://store.apple.com/us/product/MJ1L2AM/A/usb-c-vga-multip...
Unfortunately both only have 1080p HD. Let's hope there will be a (mini-)DVI version with a higher resolution soon.
So we have the "USB-C Charge Cable" $29 (http://store.apple.com/us/product/MJWT2AM/A/usb-c-charge-cab...) -- I wonder if that is proprietary or if any cable would work. Then there's the "USB-C Power Adapter" $49 (http://store.apple.com/us/product/MJ262LL/A/apple-29w-usb-c-...).
Too bad they can't fit 29W into the smaller cube form factor which charges my phone. That would be incredible powering a laptop off of that.
Someone needs to create a much sleeker implementaion of a in-line 1-port hub. So basically something that looks like USB-C on both ends, but 4" from one side of the cable there's a quarter-sized circle of hard plastic that has the USB-C cable going through it, with another USB-C port available on the side.
I hope we will see USB-C to HDMI and USB-C to DisplayPort "cables" which are not big fat massive dongles but really function more like just a cable.