http://openjdk.java.net/projects/jdk8/ ~ has the timeframe for Java8 as well as additional info.
http://jdk8.java.net/ ~ Includes the "snapshot" releases of the IDE. I'm using 80 now, as I, and others, have had issues with 81 and 82. You can also navigate all around the site and find stuff out.
http://download.java.net/jdk8/docs/api/index.html ~ here is the current Java 8 api where you can see if your request is fulfilled here(Lots of AWESOME new things included :D).
https://javafx-jira.kenai.com/ ~and if all else fails you can post here, this is Jira, it's a HUGE site dedicated to bug tracking, features, etc. This is out JavaFX Portal where we request features, post bugs, and help improve the Language ourselves.
If you really want your request this is the best place to post for it, as well as look to see if it's already been requested. Make an account, it's easy, then log in and see if it exists, if not then go post your own "issue" at the top right. I also recommend you at least check out a few already made issues. I am pretty new to Jira myself, and looking at premade issues helped me create my own.
There are a lot of new features in jafax8.
Here are some new API and features in javafx8:
javafx.scene.shape.*; //added box, cylinder
caspian.css will be replaced with modena.css
For more information take a look: