GameSpot originally did some legwork and pieced two-and-two together to find out that a tank design in Command & Conquer: Tiberium Alliances looked dead-on identical to a tank from Warhammer 40,000. Well, Games Workshop and EA have worked out the differences and there's no longer a reason to panic.
According to GameSpot, an EA representative actually did get back in touch with them regarding the issue and sprouted off the following explanation...
"Games Workshop and EA are aware of the IP issues around the artwork in question, which have now been resolved," .... "The artwork was internal EA concept art that was unintentionally released publicly. No Warhammer 40,000 tanks have ever made an appearance in Command and Conquer: Tiberium Alliances, and never will. Games Workshop and EA continue to have a strong relationship working together on Warhammer Online: Age of Reckoning and the new free to play game Warhammer Online: Wrath of Heroes which just entered open beta."
So there you have it...EA was never in the wrong, it was just some internal artwork that leaked and somehow got out into the public promotional sphere and then all kinds of legal talk started churning up about how Games Workshop was going to sue EA into oblivion (although I actually think it's just jaded gamers who felt like this and wanted some justice handed out to the seemingly untouchable publishing giant). When in reality EA supposedly never had plans to use those designs in the game itself.
In the end, like all cases involving EA and some sort of nefarious scheme, their hands are now clean (for the time being) and they're absolved of the plagiarism charges. We'll just have to go back up into our sniper perches and look out for more stuff to pin on EA as it arrives, but they sure are good at finding PR cover.