Badass Digest broke some of this a few weeks back but I'll add a little more flavor to the scoop. Some of this info hasn't made the trades yet. Figured this would be of interest in a costume forum, plus a little something to look forward to as set pics start popping up
Cap - Modified AoU suit, much simpler and cleaner than AoU design, sits somewhere between the stealth and AoU suits. Those who think the AoU suit is overdesigned will like this new version (personally I still prefer AoU). Compared to AoU, they got rid of a lot of the red highlights as well as the white on the biceps. The rest of the suit is a direct carryover from AoU, including Avengers logo, arm magnets, and gaiters. No clue on whether or not there's a helmet redesign.
Iron Man - Yep there will be a Mk46. It's essentially a modified Mk45 but with a few key changes - more gold in the torso and arms to break up the all the 45's red, smoother faceplate design (similar to the Mk3-7 helmets), and last but not least, an inverted trapezoid cutout over the round chest RT. The 45 has a hexagon cutout btw.
Black Panther - Not much change to the already revealed concept art. The suit is generally fabric throughout, with the mask being metal or some other hard material. I did get to see some early CGI work showing BP's movements. They pretty much nailed it, very acrobatic and animal-like, not quite the acrobat as Spider-Man, you can definitely tell BP's carrying more weight than Spidey as he moves around.
Falcon - Very dark costume overall, mostly dark gray with some red. Kinda reminds me of Wolvie's DOFP future costume, also has a mix of hard armor components and fabric. Wings look pretty much the same as TWS. I personally found Falcon's new look to be boring.
Ant-Man - Yes he'll be in the movie, presumably it's Lang and not Pym. Also will have Giant-Man ability. Badass Digest already broke this. Couldn't really tell if he gets a new suit, looked pretty much the same, but the new ability is most definite.
War Machine - This one is baffling to me. I've seen concept art of WM fighting Falcon where he's wearing what appears to be a new suit, but I've seen other standalone concept art for WM where it's the Mk2 suit from IM3/AoU. Guess we'll just have to wait and see.
Crossbones - Badass Digest broke this one already as well. We will see Rumlow in full costume, looks very Stevenson Punisher-esque. Black tactical gear with crossbones graffiti painted on his vest and skull design on his mask (couldn't tell if mask was a helmet or fabric). I'd say it looks pretty true to the comic look.