Wow, what an awesome list of improvements!
@ryan, I have a question about the lazy-loading of fields. Do you think this change means that the previous recommendation to reuse fields, as in the "Making efficient use of fields in ProcessWire" blog post, is now no longer needed?
Say I am using text fields in lots of different templates for different purposes, and if I create and name fields so they describe the use in each template I will have 50 text fields, or if named them generically and reused them I would have maybe 5 text fields. Is their any reason now to prefer the 5 fields option over the 50 fields option, given that in any one template I'll only have 5 text fields or less and so presumably only ~5 or less fields get fully loaded at a time?