darkSpyro

While this is too early to determine, I just wanted to make this topic for ideas on how it all may line up. I've noticed some reoccurring themes to the character releases. Also here is my guess on the waves

Undead seem to be completed within 3 waves in every game
Magic seems to have their last guy near the end (Double Trouble w3, Ninjini w4 and Trap Shadow w4)
Tech gets most of their guys out earlier than most elements
Earth seems to get most guys out early with the exception of Doom Stone
Fire also seems to be completed within 3 waves minus Fryno in wave 4
Air seems more random except they seem to get someone in wave 4 whether old or new guys
Water seems to have one or two that straggle out near the end at times (Wham Shell w5, Thumpback w3, and Freeze Blade and Punk Shock w4)
Life gets out a whole chunk of their representatives out early with usually one guy coming out later (Camo w4 and Stink Bomb w3)
Swap Force completed nearly all their Swap starter elements within 2 waves (Blast Zone, Rattle Shake, Free ranger w1 and Night Shift, Fire Kraken and Boom Jet w2)

This again is just theory, but am saying to help build confidence for anyone who's waiting for certain characters and have an idea of how the elements are divided within the waves. Anyone else have ideas can say whatever they want here.

Wave 1
Krypt King
Gusto
Wildfire
Jawbreaker
Wallop?

Chopper
Funny Bone
Blades
Torch

Wave 2
Head Rush
Bushwhack
Lob Star
Short Cut or Blastermind?

Rocky Roll?
Fist Bump
Deja Vu
Tread head

Wave 3
Blastermind or Short Cut?
Tuff Luck?
Kaboom?

Bat Spin?
Flip Wreck?
Echo?
Cobra Cadabra?

Wave 4
Thunderbolt?
Enigma?

High Five?
Fling Kong?
Trail Blazer?

Wave 5
Gearshift? Officially?

Now this is just my guess on the waves. I know it seems odd, but my theory really does make clear why those secret four Skylanders probably play a huge role in the waves. This gives an idea that most of the waves will have barely new stuff in each wave and look very unbalanced. I also figured maybe they are offering Gearshift early, but will sell her officially in 2015 as an idea that she is the last character to get as like a reversal with the previous games.

Trust me anybody if any of these make sense, I'm sure it will all work out in the end. Besides something tells me those "Unknown" element SKylanders will be the last to be released or near the end. We don't even know who they are or what element they represent so no surprise if any of those four are last.

I think your theory is probably right.
For the Unknown Element, they might be released one for each wave.

Last year they released the characters by card stats. Lowest to highest with a few exceptions.

Guarantee a magic trap master won't see the light of day until at least Wave 3. It's one of their best ways to keep the game on everyone's mind by having content that still can't be unlocked until then. That's why they waited to release a sneak movement Skylander until the later waves.

Yeo makes total sense.