It has two USB ports in the front and four in the back. It does support 30" screens and a resolution of 2594 x 1440 pixels. It as wireless (a/b/g/n) and Bluethooth and built in powersuplly so you do not need the lump on the cable, just like Mac Mini.

The box has no problem in playing video in full HD (1080p). It boots in 5 seconds. So now it remains to be seen if Apple is flattered or engaging an army of lawyers.
Chromebox costs 329 dollars while Mac Mini costs 599 dollars.
Apple is a bit more versatile than Chromebox - so you decide if it is worth the money.
