re: No Post Credit Scene for Avengers: Age of Ultron

well if we are excluding comic fans and just looking at what the MCU has shown us its a pretty limited set of characters that it could be.

Skye/Daisy/Quake (her reveal kicks off Civil War b/c Tony is mad she has so many names?)
Melinda May
Jemma Simmons
Bobbi Morse/Mockingbird
Victoria Hand (would have to be as an LMD)
Raina
Audrey Nathan (would require appearance by Coulson)
Lorelei
Sif
Jane Foster
Darcy (lol, you know you want her)
Frigga (a vision caused by Scarlett Witch?)
Pepper Potts
Ellen Brandt (maybe she survived her injuries in IM3?)
Christine Everhart (reporter Tony slept w/from IM1&2)
Betty Ross
Councilwoman Hawley (the female World Security Council member)
Sharon Carter/Agent 13
Gamora
Nebula
Nova Prime/Irani Rael
Claire Wise (unlocked Chitauri tech in one shot Item 47)
Jessica Jones (perhaps her origin for the show is taken care of here?)


There it is. Other than Black Widow and Peggy Carter that's pretty much every single female character in the MCU that has had any significant amount of screen time.

Kind of depressing really and once you take out the AOS characters it gets even worse. I almost put the waitress from The Avengers in there simply b/c she was a semi known actress from being on Growing Pains.