imo....Blizz in 2007 TBC, boosted twinking the most in all brackets with patch 2.3 or 2.4. the patch that boosted and turned hundreds of green BoP's and quest rewards into blues.
2nd boost was BoA's, even those who flamed twinks because of their end game focus were rewarded, now could near insta gear and just fill in the blanks for a twink and have one too.
in Cata if all quests are being redone along with dungeon drops.....it will be interesting, because in Cata faster leveling is the focus.
more than likely items will be boosted. i remember years ago before the mass gold infusion into the game, my 17 warrior wearing greens and some whites going into RFC with a group, barely making it thru, getting mostly level 9-13 greens and commenting how lame that was. since then mob levels and hit points were reduced, dungeons drops are much better now, dungeon rewards give a player 2 blues starting at lvl-15. anyone remember when a 60 had a hard time running you thru SFK or VC?
3rd boost imo, will be Cata.... if the BoG has near the same stats as BoA now. twinks will be all cookie cutter. XP- on floating twinks in 10-19 will also be geared the same, making that no longer appealing for the noob farmers, because the noobs will be geared