For those that don't know what Sidechains are, it's essentially a technology that would allow us to move bitcoins out of the Bitcoin blockchain, lock it in place while they are handled on a separate network, and then be able to redeem them at a later date without relying on a centralized third party. This would allow us to implement a lot more projects that aren't currently possible on the Bitcoin network without having to bootstrap an entirely new currency to do so (say, like BitShares or Ripple).
While I might've complained that Liquid doesn't live up to the promise of Sidechains, I still believe that Sidechains are a very important technology that I'd love to see on the Bitcoin MainNet and Blockstream is probably the most likely company to bring us the technology. Here's for hoping we might get the required soft-fork at the same time we fix the blocksize problem...
I loved the idea behind Tether even before I heard about Tether. It essentially boils down to having dedicated companies (gateways) focus only on fiat deposits, withdrawals and safely holding onto customer funds, while issuing digital IOUs for their deposits. This in turn would allow people to build currency exchanges and other financial services without having to rely on reinventing the wheel and also getting all the banking setup needed to create a complete product. Moreover, if you'd have multiple exchanges using the same fiat IOUs, it would be theoretically possible to have very fast exchange-exchange settlement in both BTC and fiat allowing for better arbitrage.
While I might disagree with the choice of technology and a few design decisions of how Tether operates, I'm still very much interested in seeing this concept developed further.
A bridge is a service allowing one to seamlessly transfer money in and out of a network. While the term itself is mainly used in Crypto 2.0 networks like Ripple, we have a few examples of bridges cropping up in the Bitcoin space as well - Coins.ph, Living Room of Satoshi (both outbound bridges, doing BTC->fiat), or BitWage (essentially an inbound fiat->BTC bridge). Having such bridges functional in more countries would allow us to start building some pretty interesting solutions in the near future...
Abra is a peer-to-peer remittance project (still in development) that is said to use Bitcoin in the background to do international settlement. It can develop into a very interesting project is handled correctly, possibly becoming the Uber of remittance. Unfortunately, since everything is still in development, there isn't much else to go on. Hopefully 2016 will bring us some more light on the subject.
Interledger is an interesting initiative to create a payment protocol that could work across multiple ledgers / blockchains / banking networks. If implemented correctly, it could augment the technologies like Tether, bridges, Ripple and a few others and possibly bring us some really interesting projects in the future. However, like with any project that size, I doubt we will see much progress in just a years time, but time will tell.
It seems that there are more rumours and discussions of said rumours about what R3CEV does on various social media, rather than actual information from informed sources. However, with the amount of banks involved and some of the people on the team, the project is in perfect position to deliver us a lot of interesting news over the next year.
While Ethereum has launched this year, I still think we haven't see it reach its full potential. Using it feels like a developer-grade software, rather than a consumer application. I would like to see what new and interesting applications are developed on the platform in the coming year.
Unfortunately from what I heard, the Codius project has been shelved for the time being. It was aiming to be a universal protocol and hosting standard for smart oracles, in which everyone could review the code that the oracle was to execute. This would allow for a lot of interesting projects - decentralized voting pools for cryptocurrencies, automated arbitrage bots, distributed messaging and so on. While I'm not holding my hopes up, it would be interesting to see the project revisited in the upcoming year.
So that's my list of project I'm looking forward to hearing more good news about in 2016. Beyond that, I hope we finally figure out how to scale our Bitcoin blockchain, have a mostly uneventful halvening event and not experience much of a dip in the coin price. Here's for hoping for another great year in the Bitcoin world!
To the moon!