To fans who mainly know the character of Superman from his appearances other media (radio, television, movies, cartoons), he's generally considered to have a standard set of super-powers: Strength, flight, super-hearing, x-ray/heat vision, super-breath, etc - all variations on the idea that he's simply that much powerful than an ordinary human. But in the comics, particularly in the so-called "Pre-Crisis" era, Superman would routinely manifest strange new abilities on a regular basis; some coming from his alien physiology, others from scientific augmentation. Most of these didn't stick around for more than one issue, and DC largely put the brakes on that sort of Superman story when they re-launched their universe in the mid-80s.
But now the "New 52" Superman has been gifted a new ability, as part of the ongoing Truth storyline currently underway in the pages of Action Comics.
For those who hadn't been keeping up: Superman recently saw his powers greatly diminished by the use of another new ability, the Solar Flare, wherein he is able to generate a massive destructive energy-wave by releasing solar energy stored in his cells all at once - at the price of seeing his other abilities reduced for a period afterward. Attempting to re-start his dormant powers, Superman exposes himself to a huge dose of Kryptonite, which does the trick... but has left him "altered" in ways that are still being revealed. The latest new wrinkle: He can now hear radio-waves and interpret electronic signals.
So, essentially, he now has a "x-ray vision" equivalent for his super-hearing. Superman has technically always had the ability to perceive radio and electronic signals visually (it was a novel way to track down "high-tech" criminals in the days when electronic-communication was still a new technology) but he hadn't previously been able to "read" the information being sent. However, he did have this ability once before: During an infamous period in the late 1990s, when his powers and costume had been replaced by the "Electric Superman" variation. That version didn't stick around for too long, so fans are likely not too concerned that changes like this will be permanent, either.
Other changes brought on by the Kryptonite "fix" have included short-cropped hair and glowing green eyes, both of which serve to make Superman resemble the "Eradicator Superman" from the Reign of The Supermen storyline in the 90s. A Kryptonian energy-construct who took a humanoid form similar to that of Superman, The Eradicator was one of four figures (Cyborg, Superboy and Steel being the others) who attempted to fill the role of the Man of Steel after he was believed to have been killed by Doomsday in the Death of Superman event. The reference, then, could be a clue to future story possibilities: Prior to his role in Reign, The Eradicator was a sentient artificial-intelligence who attempted to "protect" Superman by transforming him into a less compassionate, war-like "proper" Kryptonian specimen.
The future of the current Superman, and indeed the current DC Universe as a whole, has been very much in doubt in recent months. Plagued by sluggish sales and bailing creators, the ongoing "New 52" experiment has been much more poorly received than the publisher had hoped for - particularly when the high-profile of TV series like Arrow, The Flash and Supergirl along with the upcoming Batman V Superman: Dawn of Justice should be drawing more eyes to the source material. Rumors of yet another line-wide reboot have been raging for weeks, and with the traditional "comics event season" looming in the distance, it's hard not to wonder whether Superman etc are gearing up for everything to change yet again.