From jQuery JavaScript Library

• Interactions
  • Draggable
    • Distance option now defaults to 1 instead of 0, allowing for click events [#3016]
    • Fixed issue when placeholder didn't exist [#3018]
  • Droppable
    • Disabling droppables does not prevent adding the hoverclass under some circumstances [#3010]
  • Resizable
    • Distance option now defaults to 1 instead of 0, allowing for click events [#3016]
    • Fixed exception when using containment: document option [#2988]
    • Renamed autohide option to autoHide (camelCase) for consistency [#2990]
    • Renamed proxy option to helper for consistency [#2996]
    • Fixed issues with alsoResize option [r347]
  • Selectable
    • Distance option now defaults to 1 instead of 0, allowing for click events [#3016]
    • Resize callback being called too early (before element resized) [#3026]
  • Sortable
    • Distance option now defaults to 1 instead of 0, allowing for click events [#3016]
    • Unexpected behavior with sortables, when items contain wrapped lines [#3000]
    • Corrected items callback to receive standard args: event, ui [r307]
    • Stop being fired too early [#3019]
    • Placeholder displays above dragged element [#2951]
    • Placeholder positioning issues; hierarchical sortable issues [#2976]
    • Connected lists items are not refreshed until you actually move into the connected list - this improves performance for connected lists [r334]
    • Extreme performance increase [r338]
    • Fixed serialize issue when a key was specified as option, but no custom expression [r352]
    • update callback was not called every time [#3028]

• Widgets
  • Accordion
    • Various internal optimizations
    • Consistent parameters for dispatched events and callbacks. [#2340]
  • Datepicker
    • Various language file corrections [r272]
    • Allow setting of cell title via beforeShowDay [r276]
    • Fire event on change of month/year [#2876]
    • onClose bug for ranges in IE; wrapper span bug in IE; remove attribute bug in IE [r280]
    • Allow relative dates with multiple periods [r285]
    • Next link shows > when hideIfNoPrevNext is true [#2658]
    • Datepicker does not allow manual entry of alphabetic characters [#2700]
    • Date range + restricting allows invalid range [#2724]
    • Date formatting characters can be used within the prev/current/next texts. [#2593]
    • Week row hover styling [#2641]
    • When showing "off page" behaves strangely [#2371]
    • Correct datepicker placement when used in static areas; Correct select coverage in IE 6 [r311]
    • Split out display date and date value formats [#2038]
  • Dialog
    • The opening and closing of a dialog can now be animated with any jQuery UI effects, using two new options: show, hide. Currently no animation options can be supplied, only a string (the name of the effect). This issue is still in progress. [#2358]
    • Added resizeHelper [r299]
    • Added dragHelper [r300]
    • Corrected context (thisArg) for callbacks: dragStart, drag, dragStop, resizeStart, resize, resizeStop [#3017]
    • Added autoResize option; default value: true [#3025]
    • Fixed buttons so they can be changed after init using .data("buttons.dialog", ... [r341]
    • Fixed stacking problem with modal dialogs. [r343]
    • Calling open on an already open dialog no longer causes problems [#3032]
  • Slider
    • Bug on destroy [#2987]
    • Range can now be toggled on-the-fly [#3004]
  • Tabs
    • Consistent parameters for dispatched events and callbacks. [#2340] Note: This is an API change. The order of parameters for callbacks is different than previous version. Now the first parameter is Event, the second - ui interface object.

• Effects
  • Core
    • Typo in createWrapper [#2974, #2975]
  • Clip
    • Clip effect should be animating the wrapper [r292]
    • Corrected context (thisArg) of callback [r293]
    • Fix for clip to better work with images (animates wrapper for images only) [r330, r331]
  • Fold
    • Allow folding to occur horizontally first [r287]
  • Scale
    • Easing doesn't work for effects.scale [#2967]
  • Transfer
    • Transfer effect transfers to the wrong place in Safari 3.1.1 [#2983]