The version of jQuery shipped with the latest download is only v1.4.2.
jQuery v7.x is a major release. Could you make the CMS compatible with 1.7.x because that version causes CMS functionality to fail when overwriting the original source files with he latest jQuery file?
Version 1.7.x will be required for things such as Fancybox 2 etc...
you are not going to get the CMS using a different version of jQuery (without a large effort)
but you can use anyversion of jQuery in "non-conflict mode" in order to use a certain library needed that version so it doesn't conflict with the version the CMS is using
But again if you want the CMS to use a differetn version of jQuery I advise you join the dev group and put forward your suggestion there