The developers of jQuery recently announced in a blog entry that jQuery 2.0 will drop support for legacy versions of Internet Explorer. The release will come in parallel with version 1.9, however, which will include support for older versions of IE. The versions will offer full API compatibility, but 2.0 will ‘benefit from a faster implementation that doesn’t have to rely on legacy compatibility hacks.
A few comments mentioned that dropping support for MSIE 6 and 7 is fine, but MSIE 8 is still widely used by people with Windows XP. The solution to the problem seems to be conditional tags. Since jQuery 2.0 will have fully compatible APIs to jQuery 1.9, something along the lines of:
<!--[if lt IE 9]> <script src="jquery-1.9.0.js"></script> <![endif]--> <!--[if gte IE 9]> <script src="jquery-2.0.0.js"></script> <!--<![endif]-->
should solve the problem.