The SNMP trap action from LEM to anywhere (Orion included) and the connector that supports receiving SNMP trap data from Orion IN LEM shipped with our 5.4 version.
It should be described in either the 5.4 release post - Log & Event Manager 5.4 Released, Here's What's Exciting and New! - or in more detail in the 5.4 RC post - Log & Event Manager 5.4 RC Available.
If you're looking for integration beyond that, let me know what you're thinking, we're going to do more in this area.
Can we do it the other way around? Send alert from Orion to LEM / SEM?