I think the most convenient solution would be to upgrade to 8.10. It is scheduled for release in a day or two but you can get the beta if you can't wait.
Technically, you could install 2.24 on 8.4 but what is the point? 8.4 is an LTS release - and there is little of that left once you start replacing fundamental parts like GNOME.
Last edited by jay73; 10-28-2008 at 03:56 PM.