Well actually ALL items have and go by the hidden item level which can be seen with addons or a database site. So even a weapon that said "Requires level 57" Could have an item level of 60+ and would allow you to enchant with lifewarding.
"Decent Idea.. although for a hardcore quester there probably isn't that much of a difference.."
Yea in northrend there is a big difference I myself am a speed leveler and have leveled 2 characters from 1-80 since wotlk has come out getting the best time possible with 5 days played time from 1-80. If I followed this method fully with my druid I would end up with 4 days 5 hours or so. With the 2 characters before I 'hardcore quested' whenever I was online.