It would be really useful if optional and done "the right way". Just dropping it without any conversation was a bold gesture. If the work as done in improper way, it should be corrected rather than declined.
What needs to be done to make it properly:
Remove $onclick and $object arguments sed_pagination() и sed_pagination_pn(). Event handlers should be composed and binded to this event via jquery Events on document ready ($(document).ready), having chosen the pagination links with jquery Selectors. Probably, it will require some pagination data supplied via additional arguments or JS variables in the pagination block, but in in the event handler attribute.
Id is not always required to get a specific element. If document structure allows you to identify an element unambiguously with a Selector, it is reasonable to do it without an extra id attribute.
The other thing is much more difficult and is "improper use" of AJAX itself. The rule is: refresh only that data which has been changed. Generally the client script has to keep in mind what exactly is being changed, the server must return just the updated data (data but not display) in JSON or XML format; display changes are applied by client (e.g. replace div contents or add another input). The compromise solution is updating a part of a template which is being changed, but not the entire page (even if it has its header and footer off).
If I have missed some point, write it below. As the work on AJAX implementation was launched a while ago, stopping it all and saying "no-no, it must be done with fancy candy plugins" is unfair at least because there is no support for such plugins in the core (just think over the point 3). So I'd like it to be corrected regarding to this TODO list and see the task assignees here.
It is not just limited to Admin but will affect other areas too.