[support] What are the consequences of using latest JQuery?

[Eric Mckenna]

I needed to use the latest JQuery release for my front page, so I was 
able to replace the core's version with the latest for only 
page-front.tpl.php.  Later on during development, another developer 
decided to do the same replacement in page.tpl.php.  I know this is a 
bad idea, but I how do I support that it's a bad idea?  I see that some 
small issues with collapsible fieldsets on the admin and edit pages, but 
for the most part things work fine.  What am I missing??

Thanks.
Eric.