Having missed out on the first Mark III sold by Sideshow, and then seeing the cool stuff they added to the Mark II with the pop-open helmet, I was really torn because I could have gotten that one, but I didn't really like the silver look.
Thankfully, Sideshow is making Hot Toys' latest update of the Mark III figure available, and it's so super sweet. It has the opening helmet, the lights in the head and chest and hands, the pop-up forearm rockets (which appears to be reworked from the original to be more accurate), and then they added a ton of features like the pop-up shoulder pods, the expandable forearm gauntlet, a removable chest plate, the hip rotary countermeasure launcher, they reworked the leg airbrakes, they did the back propulsion flaps in metal, and it comes with a stand designed to look like the floor of the Stark Industries arc reactor from the film's finale.
So, with all my Sideshow Rewards points finally locked down, I was able to use their $43 balance to cut down on the $189 pricetag, and now I cannot wait for it to show up (its ship date is sometime in 1st quarter 2010). This may be the most extravagant action figure I'll ever buy, even beating Sideshow Vader, but dang if it doesn't look worth it.