I've spectated a number of games and Doran's Blades appear as many different items.
The first time I saw this bug, I couln't figure out why Lee Sin had 3 Meki Pendants.
Since then, I've seen Doran's blades appear as Faerie Charms and Blasting Wands.

The scoreboard at the end of the game always displays Doran's Blades so the bug only occurs when spectating.

Edit: I've now seen cloak of agility as Doran's Blades and Meki Pendants as Doran's Rings. Please fix these Doran's items!

Jax's circle that spins above him during counterstrike has a duplicate of that right above it, so what you see is two of those circles spinning. I'm not sure if this applies only to spectator mode or if it's in normal gameplay also.

Unable to spectate games on PBE

Not sure if this is supposed to be like this, but I cannot spectate on any of the featured games, when I click "Watch Now" the client goes back and I receive the following error message:

"The exception unknown software exception (0xc000000d) occurred in the application at location 0x72ce89bc."

-How you began your spectating experience: Watching someone on my friendslist
-What your current resolution and graphical settings are: Something around 900x1600
-A detailed description of the bug:
Sometimes in spectator mode, I can't scroll down. I can scroll left, right, or up, but can't scroll down, and thus must click on the map in order to move the camera, or click on other champions/use hotkeys to watch a fight going on just a little further down from my current camera view.
-The game log from the game where you noticed the bug: Unfortunately I don't have that, since it's been a few games and I'd have no idea where to look. (Also, I don't play on the computer I'm posting from.)

I also get the whispering and cursor-stuck-in-bottom right bugs.

Also, I just wanna say that I really like having spectator mode. I hadn't been paying so much attention to LoL updates before it came out, so I was really pleasantly surprised when it was released. I feel like it has potential to be a great game-learning tool; you can see item builds/strategies and how well the work (or don't work!). Keep up the good work, Riot! (:

Really tired too see if sum1 posted already but right now i had my "first win of the day" aviable, then i got to watch a ranked game randomly till the Victory of some team.
Then i noticed i didnt had the 1st win aviable anymore, tought was just mistaken, but i got into a game, won and don't got my bonus.

i'm guessing that's cause i had watched the match till the end.

sorry for some grammar mistakes, enlgish isn't my 1st language.

im not sure if this is happening to everyone but while watching spectator mode i unnoticably used up all of my bonus ip for wins. has anyone else experienced this?

-roguewalrus2

I don't know if it's already been mentioned (not wading through that many pages sry)
but I just watched a ranked game where several people's inventories showed recurve bows, which was strange. It wasn't just weird purchases for two reasons:

1- My brother was playing Lux, and denied buying it.
2- Rammus dropped a ward, and had no room in the inventory to do so, so I'm assuming the empty slot showed the fake recurve bow.

I guess it's not a huge issue, but hey, it's there.
I don't have much more information, but this showed up on:
Lux
Rammus
Alistar
Sona
Tristana
Vayne

-I dropped into a game, and the Doran's Rings were basic boots.

Screenshot Attached.
Will attached game logs when it finishes.

Attached Thumbnails

 

volibear passive says it heals for 0% if you join midgame
warmogs and tear/AA will always have 0 stacks if they finish it before you join

When I enable chat to be seen, the only chat that is visible are things said in /all chat. Team chat is not visible but I can hear the sounds that are made when something is typed into chat, so I know things are said within the team. Hopefully this is actually a bug and not something you intended. If it is then I apologize for bringing attention to it unnecessarily.