Here's a random Skyblivion developer's response to when this got brought up on their subreddit:

Going to chime in here as someone on the team in general and not necessarily as someone who leads our communications. We've made it clear our goal is to release this year; that being said, there is still work we need to finish. Ultimately, Skyblivion will be released when the team is confident with it—our goal has been to have it ready for release this year.

Now, what is "ready"? That is an ongoing conversation we have been having because the nature of a fan-made passion project is that there has to eventually be a cut-off of adding cool new things. Right now, we all agree Skyblivion isn't ready (otherwise we would release it today). Our aim is that it will be by the end of the year, if we as a team decide that it isn't we will be sure to share that.

If you're ever curious about the transparency of our work, many of our developers regularly stream, and I encourage you to check them out!

Lastly, a reminder to be nice and support one another. It is entirely acceptable to have strong feelings one way or another, but trying to take others down in the comments isn't appreciated and won't be tolerated. What has always made our community great is our shared love for Oblivion and our support of one another.

TL;DR Skyblivion isn't ready right now, but we still hope it will be by the end of the year. If it isn't going to be, we will let you all know. Passion projects are full of passionate people, and sometimes we don't always agree 100% on everything. Treat each other with love and respect <3

Just figured to add the other side of claims here.