All commentators stress the difficulty of certain skills. Certainly some of them are more prevalent now in competition than they ever were before, but extremely few were invented this side of the millenium which shows how innovative the 80's and 90's were when it did not pay to break the mould and perform a super-difficult skill. Here are the ones seen in London and their origins.
The Double Double/Silivas
This double double is currently a G skill and will be a H under the new code. In London it was performed by Jordyn Wieber, Victoria Moors, Larisa Iordache, Vanessa Ferrari and Anastasia Grishina. Though it is named after Daniela Silivas of Romania who performed it at the 1988 Olympics, it was first done by Aleftina Priakhina of USSR in 1986. Neither had great landings, but they were using a crap old floor.
Double Arabian beam dismount/Patterson
An exceptionally difficult beam dismount which requires a lot of height and speed. In London it was executed by Aly Raisman, Viktoria Komova and Marta Pihan-Kulesza. Carly Patterson of USA was the first to perform it, at the 2003 Worlds but Corey Fritzinger also of USA did it first in 2001.
Standing Full twist- beam
A move which elicited awe when Shawn Johnson did it but it's much older than that. Usually has quite a low landing due to the difficulty of fully rotating it in time. In London it was performed by Gabby Douglas. This is another skill done first by Aleftina Priakhina of USSR, again in 1986.
Tucked full twist in acro line/combination
This one is more common as it provides more momentum to get the twist around, but is just as risky otherwise. In London it was performed by Larisa Iordache. The inventor is Ecaterina Szabo of Romania who performed it in 1983.
Full twisting double layout
This is the other skill to be awarded H status in the code. Performed only by Daiane Dos Santos of Brazil but although Catalina Ponor of Romania warmed one up in podium training she never competed it. Named after Oksana Chusovitina of USSR (at the time) who performed it in 1991. It was first done by Tatiana Tuzhikova of USSR in 1987.
Li Ya Jaeger-Jaeger combination bars
Performed only by He Kexin who despite growth has managed to keep this. Often called her original skill but it was first done by Li Ya also of China who competed it in 2006.
My favourite acrobatic skill on beam, it's quite rare. Sui Lu of China performed it in London and it was invented by Cristina Grigoras of Romania in 1980. Chellsie Memmel had a nice one too.
The most common difficult skill/vault. It was performed by McKayla Maroney, Gabby Douglas, Aly Raisman, Jordyn Wieber, Maria Paseka and Viktoria Komova. First performed by none other than Simona Amanar of Romania who did it at the 2000 Olympics.
This was performed (read: sat down feet first) by Yamilet Pena Abreu of Dominican Republic in London. It is the hardest vault with a difficulty of 7.1 Notoriously difficult as it requires immense height and a powerful block. It was first attempted by Choe Jong Sil of North Korea at the 1980 Olympics but she completely crashed it so credit goes to Yelena Produnova of Russia who most notably landed it totally upright in 1999.
Def release- bars
The Def is a one and a half twisting Geinger, first performed by Jacques Def of France. His name has carried over to WAG as the first woman, Snejana Hristakieva of Bulgaria who first performed it in 1991 has a much less catchier name. It was done in London by Elizabeth Seitz of Germany. Interestingly, both perform it very sloppily but is IS possible for it to look neat- check out Cha Yong Hwa and Elena Dolgopolova.
Double Double bars dismount/ Fabrichnova
One of the hardest bars dismounts, this was performed by Beth Tweddle and Viktoria Komova in London. It was first done by Oksana Fabrichnova of Russia in 1993, and remains fairly rare.
Piked Double Arabian/Dos Santos I
This was performed by Aly Raisman and Beth Tweddle. The originator, Daiane Dos Santos of Brazil who first performed it in 2003 was in London but has not been doing it recently. It is one of the hardest floor tumbles and should be rated higher.
Full-in beam dismount
Having watched the 1996 AA all over again just recently, this was more common then. Performed in London by Catalina Ponor of Romania. It is was first done by Albina Shishova and Natalia Frolova both of USSR in 1983.
If I have missed any others in London who performed these skills please let me know. I did watch every single subdivision but some things can be forgotten easily. I have real issues about the standing full..there's no way it was just done by Gabby. As for the originators, I stand by all of them as being correct.