7 - Massive speed-ups (4x-10x) in the selector engine
8 - jQuery is no longer destructive. Doing var a = $("a"); a.find("span"); does not change the original "a" variable.
9 - Removed .oneEvent() and .unEvent() helper methods.
10 - Added new .one( "type", fn ) method
11 - Performming .click(), .blur(), .focus(), .submit() will actually trigger the browsers default action for those events.
12 - Fixed synchronous requests
13 - $.get, $.getIfModified, $.post, $.getScript and $.getJSON now all pass through the XMLHttpRequest as returned by $.ajax
14 - Improved AJAX docs (eg. more examples for $.ajax)
15 - Improved event fixing (Opera provides event.srcElement, must ignore it if target is available; only create pageX if clientX is available)
16 - Fixed ID with context selectors (eg. div #id doesn't ignore "div" anymore)
17 - Fixed nth-child selectors to start on the right number
18 - Improved jQuery.merge to avoid unnecessary loops
19 - Removed the (undocumented) .find( "selector", fn ) for all destructive methods.
20 - Fixed docs for html(): Now mentions that is not available for XML documents
21 - Improved docs for blur() and focus(), mentioning the difference between calling the jQuery method and the DOM method
22 - Implemented a better error handling for ajax requests. Exceptions caused by dropping connections are now handled, too.
23 - Added global settings for AJAX (in addition to timeout), use $.ajaxSetup() to modify them
24 - You can now unbind event handlers from within themselves
25 - Documented filter(Function), a very powerful approach for custom filtering
26 - Improved docs for FX module, merging method descriptions and marking optional arguments
27 - Improved docs for append, prepend, before and after, merging the three pairs into one
28 - Improved show/hide animations to show only hidden and hide only visible elements
29 - Added attr(String,Function) to calculate the value and support for attr("key", "${formula}") syntax, a shortcut for the former
30 - text(String) now escapes HTML per default and optionally stris tags completely
36 - Extensions to $.ajax: $.ajax accepts additonal options: beforeSend, async and processData; returns XMLHttpRequest to allow manual aborting of requests, see docs for details
37 - AJAX module: the public $.ajax API is now used internally (for $.get/$.post etc.); loading scripts works now much more reliable on all browers except Safari
38 - New global ajax handler: ajaxSend - called before an ajax request is sent
39 - Extensions to global ajax handlers: ajaxSend, ajaxSuccess, ajaxError and ajaxComplete get XMLHttpRequest and settings passed as arguments
40 - Extensions to event handling: pageX and pageY are available x-browser (IE does not provide native pageX/Y)
41 - Improved docs: $(String) method has now two seperate descriptions, one for selecting elements, one for creating (html on-the-fly)
42 - FX module: Most inline stlyes added by animations are now removed when the animation is complete, eg. height style when animating height (exception: display styles)
43 - Added note to attr(String, Object) about issues with setting the name property on input elements
44 - Seperated internal stuff from get() into set()
45 - Merged the two API examples for each() into one more precise example
46 - Improved docs for $.browser and added docs for $.boxModel
47 - Docs for the jQuery constructor $() were improved: There is now $(String expression[, Object context]) and $(String html)