I think WoW is up to iLvl500-600 now? The level cap is 90? So, in the grand scheme of things, with some exceptions, the iLv of an item simply refers to its relative strength -- the higher the better. And that's about it.

In FFXI, the iLv generally refers to what your character level would be with those stats because they can't move the cap past 99, but that's not really how it works in WoW, and though I can definitely see that's what they were aiming for with FFXIV's system, they've already started to lose sight of that, because if we were at Lv 90, we'd have boosts to elemental resistances, *all* stats, determination, and etc. and the items are not doing that. So just look at the iLv as a basic determinant of the item's relative strength compared to other item levels, not yours.