The following has been excerpted from http://www.majorgeeks.com/story.php?id=35860 :
Google will drop support for Microsoft's Internet Explorer 8 (IE8) for its
online apps and services in mid-November, effectively ending support for many
users of Windows XP [who can't upgrade to IE9]...
[This] move significantly impacts Windows XP users locked into Internet Explorer by
corporate or organization policies:... After Nov. 15, users running IE8 may have trouble with some features in Google
Apps. And if past practice is any clue, other sites and services, including
Gmail and Google Calendar, may also be affected. At some point, those apps may
stop working entirely in IE8...
The end-of-support plan for Google Apps will not disrupt access to its search
site using older browsers.
(Microsoft has committed to supporting IE8 on Windows 7 until 2020.)