While not doing kaiju-sized numbers in the USA, Pacific Rim did well enough internationally that fans of the movie had hope for a sequel. Well that hope has been boosted a bit by word that Pacific Rim director/creator Guillermo del Toro is working on a script for a sequel to the monsters vs. mechs film.
According an interview with Buzzfeed, del Toro has been working in secret for months with screenwriter Zak Penn (X-Men: The Last Stand) on the sceenplay. He reveals that the story is a sequel and currently involves the main characters from the last film, Raleigh Becket and Mako Mori, and that he is "going for very new, very crazy ideas on the second one, which are very different from the first one — but you will get really great spectacle.”
Saying that he does not have much money, del Toro still intends to try to proceed with Pacific Rim 2 (not the official title) after he finishes his next project. However, Legendary Pictures' Thomas Tull did say that the company would only make the Pacific Rim sequel if they could "crack the story [and] we all think it’s great,” and if del Toro is on board to direct it."
So, Pacific Rim not forgotten (for now) anyway.