Cisco 4500 In Service Software Upgrade (ISSU)
Came across a nifty video featuring Jimmy Ray Purser demonstrating the Cisco 4500 Sup 7E and the new single line In Service Software Upgrade (ISSU) feature.
If you are unfamiliar with ISSU, it basically lets you upgrade a router or switch to new code without taking a significant outage to reboot. In the 4500 Sup 7E, Jimmy mentions a 10 millisecond outage during the upgrade - much better than several minutes.
The video is embedded below. If you don't have flash, the link to it on YouTube is also below.
Here is a white paper that discusses the ins and outs of ISSU if you would like to learn more.