Nothing counts. At all. No stats, no enchants, no professions, no trinkets, nothing. All you have to worry about is maxing out ilvl while making sure that you wear the appropriate armor type for your class. That means wearing leather as leather wearing classes, cloth as cloth wearing classes etc. etc.
When it comes to weapons, it also matters to have slow weapons with reasonable end damage (this is regarding melee classes, and hunter). The slow weapon speed in conjunction with the end damage will more than compensate for the lack of ilvl on the weapon. Let's take rogue as an example. You want Sunstrider Axe or the Warcraft Movie relic in mainhand if you're Outlaw specced. If you're assa or sub, you want Jagged Wing Slasher mainhand. When it comes to casters, you want to equip a wand if possible. If it is not possible to equip a wand, just go by the ilvl rule.
That's basically it.
Some consumables are still usable if you choose to look into that. Food buff and flask/elixir buff still works if applied prior to entering the battlegrounds.
HF.
