The addition of the ability to just use querySelectorAll as the selector engine and not ship Sizzle is a pretty big deal, and not something I remember being included in earlier discussions about jQuery 2. qSA still includes a pretty broad set of selectors, and the ability to get the build down to 10k minified and gzipped puts it squarely in Zepto's territory, size-wise, eliminating the need for that particular wheel reinvention.