For most serious computer enthusiasts a 1000W PSU is already way overkill and now Ultra says they're going to release world's first 2000W ATX PSU at CES 2007 in Las Vegas.
The Ultra X3 Modular 2000W PSU has a footprint similar to some competitors’ 1000W units (just 10.25 inches) and is 80% efficient under typical loads. The 2000W X3 will be available to consumers sometime in early 2007.
“It’s not so much that we believe personal computers today need as much as 2000W of power,” explains George Ali, Vice President of Sales and Marketing for Ultra Products. “In fact, most household circuits can’t even provide the AC power this unit would require in order to put out 2000W of DC power. But there’s the always-inevitable questions of ‘Do I have enough power?’ or ‘Does my power supply have enough juice where my high end components need it.’ That is why we have put together this 2000W unit; as the end all of power supplies as far as DC output goes. With as much as 1800W available on the 12V alone, there should be no concern whatsoever that there is enough power available for quad core, quad GPU or large drive arrays.”
Update: I heard they're going to sell it for $499.