UPDATED 4/21/14 8PM EST
The following is for those who have NOT seen Gokaiger and want to be spoiled. If you already saw Gokaiger OR don't want to be spoiled, then don't continue reading.
The following is for those who have NOT seen Gokaiger and want to be spoiled. If you already saw Gokaiger OR don't want to be spoiled, then don't continue reading.
Most of these things are from Gokaiger and being carried on to Power Rangers Super Megaforce. Evidenced by shooting footage, them sticking to footage of Sentai with Samurai and Megaforce and also Fury Diamond saying that only Gokaiger Ranger Keys will be used and not Spirit Rangers and Titanium Ranger.
1. Ranger colors
Before Gokaiger started, fans thought that the Gokaiger would only become the color they are assigned, like Pink would only be Pink Rangers, but in fact the Rangers take the color in order of the team. For example, if the Super Megaforce Rangers become MMPR, Green becomes Black. If they become Wild Force, Green becomes Black and Pink becomes White. But when a team doesn't have Green or Pink like Ninja Storm, Green becomes Crimson and Pink becomes Navy. And with RPM, Pink becomes Black. In the case of Dino Thunder, even though there are 5 Rangers---White is considered a Sixth so Pink won't become him when they do a tribute. Well in Gokaiger, she does once, they did not use this in Super Megaforce.
If the previous Yellow Ranger did not have a skirt, Gia gains a skirt for them like Yellow Wind Ranger, Yellow Mystic Force Ranger, Yellow Mighty Morphin Ranger, Yellow Galaxy Ranger, etc. Same goes for formerly female Blue Rangers. If Noah becomes Blue Wind Ranger or Blue Mystic Ranger, he gains a male-version of the suit without a skirt. Same goes for any other suits, they gain or loose a skirt. In Gokaiger, this happens to equivalents of Navy Ranger, RPM Ranger Black, Rhino Ranger, etc. These gender swaps do not apply to the Extra Heroes like Wolf Warrior, Shadow Ranger, and Sentinel Knight.
3. White Dino Ranger, RPM Ranger Silver and Robo Knight considered Sixth Rangers
This made debate in Gokaiger and I am sure there will be more debate when Super Megaforce episodes air. The Silver Super Megaforce Ranger has 15 'sixth' rangers that help him with his powers, they appear on a special armor powerup he has. Even though White Dino Ranger is technically a fifth ranger in Dino Thunder, he is included. This was probably done to have the Dino Thunder influence in Silver's zord because he is a sixth Ranger. RPM Silver is probably included because she and Gold are a duo. Some people thought Robo Knight more of an Extra Hero but here he is considered a sixth ranger.
4. Nova Ranger, Phantom Ranger, Titanium Ranger and Spirit Rangers not included.
Even though Nova Ranger has a Japanese counterpart DekaBright in Dekaranger, she will not be featured in Super Megaforce because she did not get a Ranger Key in Gokaiger. Phantom Ranger has the equivalent of VRV Master in Carranger but he did not get a key. Fury Diamond reports that the American-made Rangers won't be getting keys, so that means no keys for Titanium, Bat, Shark and Elephant Rangers. Fans are truly sad about the exclusion of Titanium Ranger, I have already talked about that. Thanks to Morphin Madness, Phantom and Titanium Rangers will get keys.
5. The Extra Heroes
Here are the 10 that are considered 'Extra Heroes' by Gokaiger and hence get Ranger Keys in Super Megaforce: Blue Senturion, Magna Defender, Wolf Warrior, White Mystic Ranger, Shadow Ranger, Kat Ranger, Sentintel Knight, Camile, Dai Shi, and Lauren the Red Samurai Ranger. Many people wondered why Ninjor's equivalent was not included but he appears in a later episode, the Kakuranger tribute and he did not participate in the Legend War. Also people did not understand the reason the female Red Samurai Ranger was included because her powers are basically the same as her male counterpart. The idea is whoever participate in the Legend War, let go their powers and got a key. But with Super Megaforce, anything happens without explanation.
6. Aka Red
Aka Red basically means 'Red Red,' he is the representation of all past Red Rangers. He first appeared in Boukenger 30th Anniversary Special 'Boukenger vs. Super Sentai.' The logo on his chest representing the 30th anniversary changed to the 35th, he served as a mentor to Gokai Red and appeared in flashbacks and a quick cameo at the end. He only interacted with Gokai Red and Basco, a villain who betrayed Gokai Red. There has been debate among fans if he will be on the show or not. There is very little footage of him and the logo on his chest would have to be changed for Power Rangers. Fans have wanted Phantom Ranger from Power Rangers Turbo to take that place. Why? Well, Phantom Ranger was a mysterious hero with no real identity. And one of the plans for him was to the representation of past Rangers. So fans think he would fit the bill. I personally doubt we will see either. Now that 8 eps of Super Megaforce have aired, it seems we won't get either.
6. Aka Red
Aka Red basically means 'Red Red,' he is the representation of all past Red Rangers. He first appeared in Boukenger 30th Anniversary Special 'Boukenger vs. Super Sentai.' The logo on his chest representing the 30th anniversary changed to the 35th, he served as a mentor to Gokai Red and appeared in flashbacks and a quick cameo at the end. He only interacted with Gokai Red and Basco, a villain who betrayed Gokai Red. There has been debate among fans if he will be on the show or not. There is very little footage of him and the logo on his chest would have to be changed for Power Rangers. Fans have wanted Phantom Ranger from Power Rangers Turbo to take that place. Why? Well, Phantom Ranger was a mysterious hero with no real identity. And one of the plans for him was to the representation of past Rangers. So fans think he would fit the bill. I personally doubt we will see either. Now that 8 eps of Super Megaforce have aired, it seems we won't get either.
7. Lost Power Alums
In Gokaiger, all the past heroes fought in the war and gave up their powers and those powers became Ranger Keys. So the former cast alums had no powers now. But they could take their key back, their morpher would appear and they could change instantly. In Gokaiger, this happened for the three Hurricangers (Ninja Storm) and Black Condor of Jetman (which did not become PR). They might change it around in Super Megaforce. 
