Hmm...you must have misread something in my article. In fact, I wrote "the new iMac has just one more USB port than its predecessor, and in fact, the same number of on-board USB controllers". I didn't say it had the same port count as the old iMac.
I've also heard, though not confirmed, that both controllers control 2 on board USB "ports:" One controller controls two ports, and the other, the third port and the modem.
The problems still exits, especially if you want to plug into the keyboard, determining which port would be best for a given peripheral -- granted, not a huge deal, but I think it's something folks should know.
I also mentioned Jobs' "math" since this was a new equation for Apple. As far as I 've seen, Apple always spec'd the old iMac as having just 2 USB ports, and didn't include those on the keyboard.