The new intel based mac mini supports only USB - not PS2.
To connect my keyboard I had to obtain a PS2 to USB converter - and I had some issues with layout and key codes.
First - I use a normal PC norwegian layout keyboard. The key next to the left shift is the </> key. When booting the mac asks you to hold this key so it can identify the keyboard. However - it could not and had to be told which one to use (European).
Second - the layout - the mac ships with mac keyboard layouts - and PC keyboards have often a different one. This meant that where I have a '/* key the mac had a @ key. The | symbol was somewhere else as well. Following advice on the apple forums I ended up at
which suggested to download a layout from logitech. This works very well (the Logitech Norwegian layout matches the keyboard perfectly).
Lastly - still the </> key - it kept saying that it was the '/* key. Under testing on windows I found that this key still didn't work via the converter. Luckily - the converter was borrowed from a collegue - so I obtained a different brand - and this appears to work just fine.