The Toughpower 2000W was never released to retail, to my knowledge. I believe it was a CWT PUC unit just like the Toughpowers 1000W-1500W. Nothing spectacular--other than the claimed wattage, of course. But I'm pretty sure it was only shown at Computex and never sold.
The "Highest wattage" PSU released to retail is the Ultra X4 1600W, but there are serious doubts about its ability to actually reach those numbers.
The highest known honestly rated units are the Silverstone 1500W and various 1500W CWT PUC units including the Tt Toughpower 1500W, Xigmatek NRHP 1500W, and Xclio GreatPower 1500W.
The Antec HCP-1200 has been demonstrated to be able to do about 1700W, but performance suffers greatly at that load. Some other units are theoretically capable of going that high as well.
Edit: Conversation moved to new thread, think it's worth discussing on its own
Edited by Phaedrus2129 - 5/24/11 at 2:43pm