The Embedded Event Manager (EEM) is nothing new to the IOS. It has been around for a long time but is very underutilized (mostly because people dont know about it).
EEM is great way for those who love scripting and automation to make your networking devices do some interesting things. How about having a script that automatically assigns VLAN and QoS configuration to an access port when detecting an IP phone connected (via CDP)? You can do all sorts of cool things. You can have a script that disables ports at certain times of the day to save power. It doesnt sound like much, but on a large scale it could be significant (great for companies trying to work on their green initiatives). Cisco is doing some cool things in the future regarding power savings.
On the voice side, I always hated having to track intermittent drop call issues. You can look at a trace and see the disconnect from your voice gateway, so you will want to look at Q931 debugs. Looking through a syslog server full of Q931 logs isnt going to be fun. (try a call center where hundreds of calls can come in on 5 different gateways with 5-6 PRIs each). What you can do is enable the 931 debug, use EEM to parse through the syslogs and when it finds a certain cause code or calling/called number, you can have it create a file on the flash with just the info you care about. You could also have it send a trap alerting you if you felt so inclined. Much easier than waiting on the customer to alert you when they have another dropped call, only to find out the traces are overwritten