This was just posted ~3 hours ago in http://us.battle.net/wow/en/forum/topic/12675107860
I've been following this thread all week – we wanted to provide information sooner, but we try to be discreet when it comes to measures taken to address exploits and game abuse. We applied a band-aid fix last week to scale down the drop-rate of Uncommon, Common, and Poor (green, white, and grey) items inside Burning Crusade raids and dungeons, proportional to group size – this is the same way gold works, and if you had a full 5-player party running a dungeon nothing would have changed, but if you were soloing a raid like Black Temple you would have seen a large reduction in vendorable items. Clearly that change, particularly undocumented, impacted innocent players. With today's maintenance, we've reverted that temporary fix and replaced it with an approach that should have zero impact on legitimate players.
That said, while we're very supportive of the activity of running legacy content, whether for transmog gear, crafting materials, trying to get that elusive second Warglaive, or just seeing places you never got to experience the first time around, we do need to keep an eye on the gold rewarded in the process. The core issue is that dungeons and raids yield much larger quantities of loot and materials, because they're designed to be split among 5, 10, or 25 players. But when you can go back and solo them later on, they can end up being disproportionately lucrative. We want them to still be rewarding and profitable (and clearly getting 3 grey drops from a full BT clear this past week was well short of that), but we may adjust the vendor-loot yield of legacy raids going forward into Warlords to keep the overall economy balanced. In any event, we'll provide much clearer documentation and advance notice if and when we do that.
Apologies for the radio silence regarding this change over the course of the past week.