Using the /summon or /setblock command to spawn a dropper or a dispenser works but data tags cannot be used to specify the orientation.
To replicate:
Create a command block containing any of the following commands:
setblock ~2 ~ ~ minecraft:dropper 1 replace
summon FallingSand ~2 ~ ~ {Time:1,TileID:158,Data:1}
Both will spawn a dropper facing in the default direction of South, regardless of the value of Data (if placed against a wall the dropper will adjust to face away from the wall). Applying the data for repeaters, hoppers and comparators work fine.
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I can confirm this as well and would really like this to be fixed. Very frustrating.
Confirmed for 13w41a.
Bug still persists in 13w43a
Confirmed for 1.7.
Confirmed in 1.7.1.
Still present in 1.7.2

Confirmed for snapshots 13w47a/b/c.

Duplicate of https://mojang.atlassian.net/browse/MC-12437
Hey took nearly 20k tickets for it to get run into and reported again. I feel proud about that! This was happening back with redstone-activated spawners, pretty crazy that it affects /summon and /setblock too. Glad it's finally getting some more attention. I really hate this bug 😛
I would say leave this open until it's possible to transfer the 11 votes plus Confirmation status over. This ticket's significantly more active/progressed.

hey guys, vote for this issue and it will get more attention from mojang!
Confirmed for 1.7.4.
yes, also confirmed 1.7.4

Confirmed for 14w02c

Confirmed for 14w02c
Confirmed for 14w04b
Confirmed for 14w04a

Confirmed for 14w05a

Confirmed for 14w05b

As per MC-42375, this also appears to affect rails.

Confirmed for 14w06a

Confirmed for 14w06b as well.
Confirmed for 14w07a.
Confirmed for 14w08a.
Confirmed for Minecraft 1.7.5.
The problem shows still in 14w10c.
Used command:
setblock 11 45 87 chest 2 replace {Items:[{Slot:0b,id:torch}]}
And its' facing is 3 instead of 2. (It's 3 everytime).
It's still in the 14w11b snapshot as well. It makes it impossible to place single standing dispensers in the correct orientation.
I'd recommend using /clone as a temporary measure til this gets fixed. It seems to use the right direction.
That would probably work for now. Thank you for the tip No Way.
Confirmed 14w11b
Still present in 14w17a.
Clone does not respect orientation with rails. There seems to be 2 separate issues here, one where the setblock command doesn't respect orientation of some blocks, and one where rail's default behavior is overriding the behavior of the setblock and clone commands.
Confirmed for 14w18b.
confirmed for 14w19a
Still present in 14w26b.

Fixed for all but the rails.
Confirmed