Hey Thane Soren!
First off, thanks for taking the time to voice your feelings on the boards.
Unless you count the people that say "But there's SK-" NO. No. It's a limited edition 750 skin. It's been out of the store for god knows how long. Zed is the only Season 2 champion that technically has only one skin.
Yes, technically, Zed's last skin was May of 2014 (SKT T1 Zed). It's legacy, not limited, which means it can, and likely will make periodic returns to the store. That said, I understand the frustration around that skin - it's a World Championship skin, and it's not currently in the store, leaving you with Shockblade Zed.
I look at Thresh mains and Ziggs mains and wonder what goes through their heads. "Gosh, which of my fifty skins do I feel like playing right now?"
Sure, they have multiple skins, but in their defense, Ziggs hasn't had a skin since December of 2012, and SSW Thresh is part of a World Championship skin line, which is decided based on champions the winning team played.
And then there's Zac.
Along with Zyra, these are some of the most difficult champions in the game to work with.
I'm sure you've heard this a million times before, but due to Zac's unique model (stretching with textures, etc), we're presented with some difficulties. However, that's not to say we'll never make a Zac skin again 'cause that's simply not true. It's been a long time since his last skin (since his launch!) and we want to give players an awesome skin that really does this goo guy some justice. (We did something similar with Star Guardian Lux - we wanted to really put out a skin that not only did the champion justice, but really made it worth the wait for a new skin.)
Unfortunately, I can't say what may or may not be in the works for Zac, or any other champion.
I remember a post by Ironstylus saying that Zed isn't all that difficult or complicated to create a skin for, either.
He's not the easiest, but he's not as difficult as the aforementioned champions. That said, there's a lot of cool ideas floating around, and it's easy to say, "just make this skin, or this one." Sure, we could slap various thematics on Zed, but is it really the best option for him? We strive to make the best skins we can, rather than just tossing a new skin on a champion because 'it's been a while'.
In addition, if we have a cool concept for, let's say, Snowdown, we'll hold off on putting the skin out until December when the event happens, since that makes the most sense.
And if Riot just goes out and tells us the status of a skin for a champion we like, they can potentially lose money because people will be like "oh I'll save up for whatever Zed skin is coming." The fact that we don't know is what helps them get more money from us.
We don't announce champions or skins prior to them hitting PBE because a lot of things happen and change behind the scenes. We may have a concept for a skin, and we start working on it and realize it's not working as we thought it would, and we either shelve it to try again later, or start on another idea.
If I said, "hey guys, we're making Star Guardian Zed!" and then a month later I say, "Sorry guys, we won't be making this any longer, but now we're going to make Guardian of the Sands Zed", there's going to be some negative feelings surrounding the decision. Some will be happy that we're not making Star Guardian Zed, and others will be pretty upset that we 'promised' the initial idea.
By holding off until the content is finalized and ready for its debut, it alleviates a lot of the negative feelings that could happen if skin concepts change for a particular champion, or if the concept for a champion changes.
Hopefully this clears up some of the frustrations you have. I know it won't clear up the fact that Zed only has one available skin at the moment, but I can promise you that there will be more Zed skin in the future!
If you have any addition questions or comments, I'd be happy to hear them. :]