this page contains links to most important SharePoint 2013 (Wave15) resources I currently know:

• Download-Links to SharePoint, Lync, Project, Exchange, Visio, Office in one Page
• TechNet Collection: What`s New
• SharePoint Developer  & IT Pro Training Modules & Presentations
• Official Press Release about new Office
• Microsoft`s Search Results for SharePoint 2013
• AppStore
• Installation Tipps & Tricks: Eric Harlan, Andreas Glaser
• Vesa`s Collection of Training Material & Videos for IT Pros and Devs
• Discontinued features and modified functionality in Microsoft SharePoint 2013 Preview. Changes from 2010 to 2013
• Blogpost Announcement from Jeff Teper about new Features (subscribe to the SharePoint Team Blog!)
• Tech Library HelpFile
• Start building Apps! Find here samples
• free eBook:Deployment Guide
• Upgrade! Process /  Test Upgrade  / Worksheet