actually most top progression guilds use loot council to gear their raids up. whoever can use an item and be the biggest upgrade for gets the item, be it a dps, tank or healer. this system spreads out the loot to where you gear your entire raid evenly and most effectively.
the notion of gearing tanks up first no longer applies in wotlk like it did in bc. sure, if your tanks cant take the hits then you're going to wipe. but if your dps isn't up to par on some fights you'll bang your head against enrage timers, or healers won't be able to last or outheal incoming raid damage. it's a balance these days when it comes to how to gear up your raid.
getting a loot system other than /roll is your best option and will avoid loot drama. suicide kings and epgp are possibly the fairest and easiest systems to use. they also balance the loot distribution to a point (if a dps is higher than a tank then they will get the tier token and vice versa) to where your raid will evenly gear up.