Ideolo of NEKO WORKi released an all Touhou illustration book for Comiket 78 called Carnival Fantasy which for the most part features colorful single character illustrations of many of the main Touhou girls. Ideolo has an interesting almost paper cut-out like style to his illustrations, and it really shines in this collection with stylized backgrounds to match.
Koto was first talked about here with her Pixiv Market release, Marchen, which featured all original illustrations. This time around, Koto has released Partita Vocaloid Fan Book, a full color collection of Vocaloid illustrations that includes tributes to many of the popular songs like Magnet and Eager Love Revenge along with the new design for Hatsune Miku Append.
I was first introduced to Ein's art work through the art book The New Generation of Manga Artists Vol. 4: The Omnibus Collection, a publication I'm sure many other anime fans ran into at some point. While Ein's signature style is beautiful girls in hi-tech scenery, it's not always in demand and his art work outside of light novel covers can be hard to find, so I was delighted to see his Long-Cake Pico Pixels doujinshi release for Comiket 78.
V-Edition 03 Rainbow Lips Books was released by the former Supercell illustrator 119 (Hikeshi) during Comiket 78. It's a full color collection, and unlike his V-Edition 02 release, it's a book instead of a digital collection. Call me old fashioned, but I still can't bring myself to pay good money for small images burned onto a CD.
We Love Mow Mow is a collection of charity illustrations drawn to raise money for farmers who lost livestock during the 2010 outbreak of foot and mouth disease in the Miyazaki Prefecture of Japan earlier this year. Thousands of cattle and pigs were slaughtered to curb the spread of the infection, and farmers bear those costs. All of the profits for We Love Mow Mow were donated, the bulk of which were received during Comiket 78.
I don't know what it is about trading card game illustrations, but I've really never been interested in them. So knowing ahead of time that Ar Tonelico illustrator Nagi Ryou's Comiket 78 release T.U.R.N Collection of TCG Illustrations would be exactly that, I wasn't initially committed to buying it. It didn't help that the resale price for the doujinshi on Toranoana was ￥1470, which is really quite high for a 24-page doujin considering I've bought new art books for less.
Even though Toranoana's ALL SEASON MIX BEST is really about the music, I had to get it for the accompanying art book full of all new original illustrations from artists like You Shiina, refeia, H2SO4, Tiv, Kuroboshi Kouhaku and many more. There are 39 illustrations in total from 27 artists, so in some cases you may get to see a new illustration from a favorite artist more than once ^^
Released for Comiket 78, SEN茶 (SENTYA) Illustration Book 5 is Chiba Sadoru's fifth illustration volume, but his first done in all color. Previous volumes contained only four to six pages of color art work, with the rest in black and white but SEN茶 Illustration Book 5 is 24-pages of color art works in a B5-sized collection.
For Comiket 78, Miyu released another installment in her visual book series, Mitsu*Mitsu, featuring a collection of all original illustrations. While Miyu isn't that well-known, she has been one of the contributing artists for Etsu Magazine's themed galleries, which later go on to be in the volumes of Girls Girls Girls! Illustrations books. She actually had one illustration in the most recent book.
Although Akabane is a relatively new artist and doesn't have a lot of work to her name, her Comiket 78 release RE Concerto the Idolmaster beautifully displays her talents for anyone wanting to look. It's a relatively short collection---just 16-pages including the covers---that focuses on beautifully detailed and fleshed out illustrations of The iDOLM@STER characters.