jQuery 1.9.1 (currently in WordPress 3.6 development builds) removes some core functions that many plugins rely on, and that includes live() method for event binding, and all other bind related functions. In jQuery 1.7.1 a new method is added: on(). So, we need to have all plugins jQuery code updated to use on() instead of live() and bind(). jQuery 1.7.1 is shipped with WordPress 3.3. And because of that, all plugins will get updated jQuery code that will require jQuery 1.7.1 and with that will require WordPress 3.3.
Currently, there was a plan to change requirements for some plugins to WP 3.3, and that plan will go ahead earlier than planned (GD Products Center and GD bbPress Toolbox). And some plugins already require WP 3.3 (GD Custom Posts And Taxonomies Tools 4.1 Pro that will be released this week). But, now all that is changed, and there will many updates during April to stay ahead of WP 3.6 launch. It is very possible that WP 3.6 is not going to be released until late May, depending on how many delays there will be.
During March there are 3 releases planned:
- GD Products Center 1.2.1 (March 26), it will still work WordPress 3.2.
- GD Custom Posts and Taxonomies Tools 4.1 (March 27), it will require WordPress 3.3.
- GD bbPress Toolbox 1.5 (March 31), it will require WordPress 3.3.
In April more updates are coming, all will require WordPress 3.3:
- xScape Theme Framework 1.9.2 (middle of April).
- GD Products Center 1.2.2 (in late April).
- GD aZon Fusion 0.9.7 (in early April).
- GD Affiliate Center 1.4 (in late April).
- GD Simple Widgets 2.2.1 (middle of April).
- GD Press Tools 4.4.2 (in late April or early May).
- All 3 bbPress free plugins (first week of April).
- Other free plugins that rely on jQuery (in late April).
Some of these plugins all rely on jQueryUI, and they will also get latest available jQueryUI.
And in the future, plan is to limit support for maximum of 4 versions of WordPress. Once WordPress 3.7 gets in development, minimum required WordPress for plugins and themes will shift to WP 3.4, or WP 3.5 (for some plugins, depending on what they need or do).
My suggestion is to make sure that other plugins you use are also ready for the WordPress 3.6 transition, since now you need to worry about jQuery too, and I think that a lot of plugins will not be ready for such upgrade. Try to reach to developers of plugins you use and remind them of the upcoming changes to WordPress so they will have enough time to prepare for it.