I just downloaded the 3.3 beta 3 version and noticed that jQuery 1.7 has been included.
In my opinion, it is too early to include version 1.7 which has been released just a few days ago - the world hasn't updated their plugins yet to be compatible with this version.
For example, many of my themes use the Nivo slider jQuery plugin which is not compatible with jQuery version 1.7 - if WordPress 3.3 goes out with this version of jQuery, not only my themes, but thousands of other themes that use this plugin (it is really a popular one) will look broken.
I will let the developers of the plugin about this bug and hope they will be able to release an update until WordPress 3.3 is released, however I'm sure there will be lots of other jQuery plugins that won't be jQuery 1.7 compatible and we will have lots of problems.
Isn't it better to give the world first some time until all the jQuery plugins are compatible with 1.7 instead of creating such a hassle with the next WordPress release?