There have been a lot of rumors that Tony Stark actually wears armor Mark XLII in Iron Man 3, and there could be many, many Iron Man suits featured in the movie. Now, someone on 4chan has posted details they claim describe many of these suits, and even included concept art for some of them.
At this point we're assuming these are fake, but they still look very cool. And who knows? Maybe they'll turn out to be more than really great fan art.
One more warning — just reading these descriptions will give you a pretty complete summary of the movie, and there are a few specific plot details that will be spoiled as well (again, assuming this stuff is real). Just so you know.
MARK XI - STEALTH ARMOR v.01
• A derivation of the MARK VI armor, TONY STARK configured it to have built-in stealth capabilities, which allow him to infiltrate the TEN RINGS' hideouts unnoticed.
• Slightly modified Mk.VI, with a dark blue color palette. Red eyes and Arc Reactor.
MARK XXII - LAYERED PLATING ARMOR v.01
• Experimenting with various forms of armor formation, TONY STARK designs this armor with the concept of retractable layers. This technology allows this armor to fold into a more compact form, making it more portable than the MARK V armor.
• Classic/Spandex Armor, v.01 has the horned face, v.02 has the rounded face with a different color palette
MARK XV - STORED KINETIC INTEGRATED NETWORK (S.K.I.N) ARMOR
• Attempting to create a new form of malleable liquid metal that could be configured into other shapes, TONY STARK creates the S.K.I.N ARMOR. Unfortunately, the alloy compound proved to be unstable, resulting in TONY STARK putting the project on hold.
• Looks like the comic SKIN Armor, but slimmer and more segmented. Huge shoulder armor.
MARK XVIII - SPECIALISED AQUATIC ARMOR v.01
• Designed with the sole purpose of undersea exploration in mind, TONY STARK builds the SPECIALISED AQUATIC ARMOR. Able to withstand greater pressures than his standard armors, IRON MAN travels deep into the sea to recover rubble from MANDARIN's attack.
• Hydro Armor. Resembles the comic Hydro Armor, but sans the glass fishbowl helmet.
MARK XL - ASGARDIAN DESTROYER ARMOR
• Taking into account that Earth might face future threats from the ASGARDIANS, TONY STARK set about designing an armor specially to take down any invading ASGARDIANS. Using the DESTROYER's blueprints stolen from S.H.I.E.L.D's HELICARRIER, STARK creates the ASGARDIAN DESTROYER ARMOR
• A mecha version of the Destroyer seen in Thor. Incomplete prototype.
MARK XXXVI - HEAVY DUTY BRUTE ARMOR v.02
• Designed for heavy duty tasks that his standard armors cannot handle, TONY STARK creates the HEAVY DUTY BRUTE ARMOR with sheer strength in mind. Equipped with state of the art hydraulic systems powered by a modified ARC REACTOR, this armor enables IRON
• A.K.A the Hulkbuster Armor. Not explicitly termed as the Hulkbuster though, since that's not the intended purpose. It's prototype is the Mk. XXII / v.01, and is smaller and more humanoid.MAN to take on the strongest enemies.
MARK XLII - X01 - PARTICLE RADIATION CANNON ATTACHMENT
• Unable to deal with FIREPOWER's fiery attacks, TONY STARK designs the PARTICLE RADIATION CANNON to absorb and channel TAGGERT's heat against him
• A huge cannon that attaches to the Mk.XLII's chest. Based on Bleeding Edge's cannon.
MARK XLII-R - RAPID EVACUATION SITUATION CONTROL UNILATERAL ENFORCER (R.E.S.C.U.E)
• A custom-modified variant of the MARK XLII, created by STARK to facilitate PEPPER's rescue from A.I.M after their experiment.
• Feminine version of the Mk.XLII. Has firefighting functions.
MARK XLV - HYPERVELOCITY AUTONOMOUS PERSONNEL PROTECTOR γ (H.A.P.P.γ) ARMOR
• Mourning his dear friend HAPPY HOGAN's death, TONY STARK creates this armor in the image of his deceased friend. Equipped with its on A.I. programmed after HAPPY's neuro patterns, H.A.P.P.γ assists IRON MAN in his battles.
• Looks like a hybrid of the comic Telepresence Armor, and the Mk.VII. Gets thrashed by Coldblood.
MARK XLVIII - HEART BREAKER v.01x
• Created using various parts and components from his damaged IRON ARMY suits, TONY STARK assembles a unique armor with high offensive capability. Armed with a larger ARC REACTOR with higher energy output, IRON MAN is ready to take on his most dangerous foe: THE MANDARIN.
MARK XLVIIIs - SPACE ARMOR v.01
• After experiencing the CHITAURI attack in THE AVENGERS, TONY STARK has been working on a suit capable of space travel. Crafted using a unique new metal alloy that absorbs his ARC REACTOR energy signature, IRON MAN travels into the far reaches of space to find the source of a coded SOS he receives.
• White/black/gold armor, which has the concept art leaked recently
MARK XLIX - HEART BREAKER v.02
• Having his armor badly damaged in his battle with the MANDARIN, TONY STARK modifies and upgrades his HEART BREAKER ARMOR into its second version. Equipped with more ARC REACTORS to increase its output and offensive capability, this is the ULTIMATE IRON MAN.
• More cohesive version of the Heart Breaker armor. Color palette based off the initial Ultimate Iron Man armor.
MARK L - EXTREMIS ARMOR
• Perfecting the EXTREMIS technology at long last, TONY STARK is finally one with the IRON MAN ARMOR.
• The true Extremis Armor. Hybrid of the comics' Bleeding Edge and Extremis Armors.
MARK LI - ORIGINAL ARMOR [ REVISITED]
• After DR.HANSEN disabled all the EXTREMIS technology, TONY STARK is left unable to tap on his newer EXTREMIS-based suits for battle. Having no other options, STARK dons the REVISITED ARMOR to finish his fight with THE MANDARIN.
• More techy, solid-looking version of the movie Mk.I. Based off the comics' first armor.
Much thanks to Dex-Starr for the tip!