First off, he confirmed that, as written now, the script will feature a rather lengthy appearance by Cap's WWII super-team The Invaders. According to an article at Chud.com, Johnston has said the classic team "will be in the entire second half" but did not reveal which members would appear, saying only that there will be six Invaders in the film. Around the same time, he revealed that he's aiming to cast an unknown as Cap/Steve Rogers and surround him with more recognizable faces in supporting roles. He also said that, as the bulk of the film takes place in Europe, he'd be shooting in London. AICN is also reporting that the bad guy of the film will be The Red Skull.
What's more evil than Nazi? Nazi Vampire, bitches.
Finally, Hero Complex has a great little interview with Johnston about the costume that the prospective Cap will don in the film, and he reveals that Cap will wear two; one closely based on the uniform as it appears in the comics, and one more modified for film.
Here's some excerpts:
The costume is a flag, but the way we're getting around that is we have Steve Rogers forced into the USO circuit. After he's made into this super-soldier, they decide they can't send him into combat and risk him getting killed. He's the only one and they can't make more. So they say, 'You're going to be in this USO show' and they give him a flag suit. He can't wait to get out of it...So he's up on stage doing songs and dances with chorus girls and he can't wait to get out and really fight. When he does go AWOL, he covers up the suit but then, after a few things happen, he realizes that this uniform allows him to lead. By then, he's become a star in the public mind and a symbol. The guys get behind him because he embodies something special...He realizes the value of the uniform symbols but he modifies his suit and adds some armor, it will be closer to the Cap costume in some of the comics in more recent years...this approach, it's the only way we could justify ever seeing him on a screen in tights, with the funny boots and everything. The government essentially puts him up there as a living comic-book character and he rips it off and then reclaims some of its imagery after he recognizes the value of it. We think it's the best way to keep the costume and explain it at the same time.
I actually think this is a solid approach. Look, translating comic book super hero costumes straight to screen has never worked. Well, once. It worked for Christopher Reeve, but he's the stellar exception. Okay, and Iron Man, but he's a dude in a robot suit, not tights. You have to modify these things, and this at least seems to make sense.
The rest of the the news, The Invaders, the Skull. Man, they sound kick-ass. Done properly, the Red Skull might be the only comic book villain that looks better on film.