Valve's Doug Lombardi has told Eurogamer that you won't see a new Portal this year.
Instead, the developer will knuckle down and try to do something as revolutionary as Half-Life 2 was to the original Half-Life - because that's the Valve way.
"In typical Valve tradition, it won't be Portal with different colours," said Lombardi, dressed as a companion cube. "I think that when you hit something like that, you have two choices: you can quickly replicate it and stick it out there - do the opportunistic thing and cash in on it; or you can do the crazy thing like we did after Half-Life was so successful and go off and try and say, 'Okay, that was revolutionary, so its successor has to be equally as revolutionary.'
"That's the spirit I think we're approaching it in," he added. "You won't see a new Portal at retail this Christmas because of that. That's the trade off. People want more, but we don't want to give them more of the same right away because that would just be boring."
Portal was released last October and Valve was surprised at the effect it had; Lombardi says it shocked him to see people dressed as companion cubes as soon as a week or two after release.
The original game - described as an "experiment" - went very well, then, and now Valve is doing plenty of research and development to find out what "more" it is going to offer.
"I think you have to be ambitious. For us, that's really paid off. Half-Life 2 was the right decision, it was painful, six years and upwards of 40 million dollars to develop, but that paid off. That's our recipe," concluded Lombardi.