Connect. Plug. Play.
Mac mini works with both Mac and PC-compatible peripherals, so it’s easy to upgrade from an older Mac or PC system. Simply connect your USB mouse and keyboard, then hook up your DVI or VGA display (adapter included).
I can already see two funny support issues coming:
-- "I connected my PC keyboard but I can't find this key with an apple on it"
-- "No, you cannot place your 23' monitor on top of the Mac mini. Yes, we know it's tempting, but no."
By the way, thanks to the weak dollar, the Mac mini is priced at 499€ here, 19.6% VAT included. This represents about 15% markup on currency exchange, which is less than Apple's traditional policy on hardware, though the software is now much more expensive (at 79€ for iWork, it's almost three times the usual markup on currency exchange).