Currently shows the blizzard's reported item level, item level as calculated by the addon, and the item id with more planned for the future. It is a great way to tell if items are severely off from their item budget.

Some stats are not yet supported such as extra armor (common on tanking rings) and procs/uses can't realistically be supported. Meta sockets are considered 20 of an invisible stat and all other sockets are considered 10 which although seems a bit high, still results in lower then expected item levels for the majority of gear.

Weapon dps sacrificing is now supported but it is assumed all +dmg or +healing on the weapon is gained through sacrificing if the melee dps is lower than expected although their are some weapons that have additional +dmg or +healing. This was a tradeoff I had to make because weapon melee dps isn't very consistent so it can't be determined exactly how much caster +dmg or +healing was gained through sacrificed melee dps.

To turn debugging on type "/script ItemTips.Dev = true" without the quotes into your chat window and then it will show you the stats it found so that you can see if any are not being counted.