No, this isn't a belated April Fools joke. id Software has really sold itself to another company. Not just any company, either. The lucky buyer happens to be ZeniMax Media, the parent firm of Bethesda Softworks and Bethesda Game Studios—you know, the guys who made Fallout 3, Oblivion, and the rest of the Elder Scrolls series.
According to the official announcement, the acquisition is already a done deal. id Software remains under John Carmack's direction with no operational changes. id "principals" have signed long-term contracts to stay on board, and Bethesda Softworks gets to publish id titles "other than upcoming releases previously committed to other publishers." (Read: Rage, to which EA has publishing rights.)
So, why the merger? Still id Software CEO Todd Hollenshead provides part of the explanation in the press release:
This was a unique opportunity to team with a smart, sophisticated publisher like Bethesda Softworks where the interests of the studio and the publisher will be fully aligned in the development and marketing of our titles. In addition, we will now have financial and business resources to support the future growth of id Software, a huge advantage which will result in more and even better games for our fans.
John Carmack also chimed in with a more detailed, albeit a little less PR-friendly, message:
We will now be able to grow and extend all of our franchises under one roof, leveraging our capabilities across multiple teams while enabling forward looking research to be done in the service of all of them. We will be bigger and stronger, as we recruit the best talent to help us build the landmark games of the future. As trite as it may be for me to say that I am extremely pleased and excited about this deal, I am.
As for ZeniMax's CEO, he says his company will both provide publisher support and "give id Software the resources it needs to grow and expand." In short, this move seems to be more about id's plans for expansion than anything else.