Dlcui new portal
You're referring to the new DLC (Downloadable Content) for the popular game Portal!
As of my knowledge cutoff, the latest DLC for Portal is "Portal: Still Alive", which was released in 2008. This DLC adds new test chambers, puzzles, and challenges to the original game.
However, I must inform you that there hasn't been any official announcement from Valve Corporation, the developers of Portal, regarding a new DLC or sequel to the game. The last main installment in the series was Portal 2, which was released in 2011.
That being said, there have been rumors and fan-made projects that have attempted to create new Portal content, such as fan-made levels and mods. These creations are not officially sanctioned by Valve, but they can still be a fun way to experience new Portal content.
If you're looking for more Portal-related content, I recommend checking out the Portal wiki, which has a vast collection of fan-made levels, puzzles, and other creative works. You can also join online communities and forums dedicated to the game to connect with other fans and learn about new developments.
Keep in mind that any new Portal content would require significant development and testing from Valve, so it's unlikely that we'll see a new DLC or sequel anytime soon. However, the Portal community remains active and creative, and there are always new and exciting things to discover in the world of Portal!