Completion can be performed within a brace expansion. To match a number use . If you preferred the old behaviour you can alias cd to pushd. See the description of IFS in the zshparam manual page for more details. Programmable completion allows detailed control over what arguments of what commands can be completed to what.
Qualifiers can work on links or on what they point to.
Qualifiers separated by commas are or-ed. Bindkey can now bind both key sequences and prefixes of those. You can for example bind ESC and function keys sending ESC sequences. Additional options to read builtin to use in functions called by completion. New options to print to sort arguments and print them in columns.