There's a couple theory threads around, but to be fair nobody but Blizzard knows...
I've played a few hours of the new patch already, dropped 1 Legendary on my MF DH, so as far as I'm concerned it's pretty much the same. Legendary items on the AH also haven't dropped a lot as well (but then again, it's only been 1 day).
Btw "wait for it" reminds me of Witch Doctor, Shadow Demon and Zeus' quotes from Dota 2
From all accounts I've heard people have been getting loads of legendaries. Heck, Renesco from these forums was telling me about his 6-8 legendaries he got last night... that's... a lot.
I played for 30 minutes with 20k dps (still mostly naked) and even I got a legendary. I don't expect prices to drop until at least a few weeks though. It will take awhile before the increase in supply is noticed. Also, new players are entering the market with the new patch hoping to buy gear so that drives up demand. Honestly, prices should be increasing right now.
Dropped in 1x Alkaizer run with added on keywarden
- 1x Key
-1x Set belt: Immortal Kings
- 1x set weapon: Chantodo's wand
-1x WD helm (ilvl 62 crap)
- 1x Monk helm (Tzo K something)
So the drop rate is markedly higher, but it was similar in the first 2-3 days of 1.04, whereafter Legendary drops went down a lot, so I will wait before I say its massively increased, but at the moment it seems that with extra MF from MP and double drop rate, at high mf it has a very high legendary drop
I ran act 1 4 times at monster power 4 with 355% MF and got 4 legendary's, 3 bad ones one Immortal Kings Belt. Played maybe 2 hours. I used to get 1 legendary every 3 runs of act 3 in patch 1.04. so definitely much more noticeable.
within two hours me and a buddy got 1 set (innas belt) 4 legendaries (depth diggers, a 1350 dps high str skorn, dex andys helm with socket, and the uhkapian serpent mojo) along with all 3 keys and the plans. Yep, loving this patch =D
Strangely enough I haven't found any since the patch. I generally got 1 - 2 per farm session. Now I have yet to see any legend drop yesterday or today. Not really worried about it though, I would rather get good ones than tons of crap ones.
The massive increase in drop rate is good for poor people like myself however. Soon we will be able to gear up for next to nothing!