I don't know about the rules changes, but I absolutely hate the name "One D&D." It reminds me of techy nonsense jargon, as if they were trying to launch a new Xbox. I'm not a fan of .5 editions either. If it's been 10 years and you're dropping new revamped sourcebooks with major rules changes then call it 6th Edition, and don't try to pull a fast One on us or confuse our handy two character 6E abbreviation. I feel like they are tempting fate with that name change, and someone needs to check them on it before it goes to print.
