Just came across this. The hyperbole in the article - and also from the publisher - is overblown. This two-volume set is not the major "groundbreaking achievement" it is being made out to be.
Don't get me wrong. The book, HaMafteach by Daniel Retter, is a great idea, and I can easily see myself purchasing it at some point in the future. I hope it sells well. However, the reality is that there already are a number of popular and widely accessible works available that function as Talmudic indexes (and most cover other major sifrei Chazal as well).
For Biblical verses there is the Torah Temimah from R' Baruch Epstein (d. 1941), which cites all the major Talmudic discussions on any verse in the Pentateuch as well as many from other sifrei chazal. (And, of course, there is always the Toldos Aharon, printed in any Mikraos Gedolos. And the comprehensive Torah Shelema from Rav Kasher.)
For biographical and historical information, there is the classic Seder HaDoros by Rav Yechiel Heilprin (d. 1746), which has a detailed chronology of Jewish history from Creation through the 17th century as well as a comprehensive encyclopedia, in alphabetical order, of the Sages of the Mishna and Talmud. It is available in clear, modern prints and should be in every serious Torah library.
For halachic topics, the Rambam's Mishneh Torah (with the Kesef Mishnah) will quickly point you to the relevant talmudic sources (and, with the Shabsai Frankel editions, beyond). Similarly, the Sefer HaChinuch, especially the newer editions of the Minchas Chinuch, will quickly enable you to find the Talmudic references for any mitzva.
For aggada (non-legal material), the best index is the three volume Otzar Ha'agada published by Mossad HaRav Kook. This is a topical index of all aggados, including midrashim and Zohar.
These references are all far more comprehensive than HaMafteach can be; after all, it's just two volumes and the sample page shows that it is not tiny print. However these works are also more specialized than HaMafteach, and, generally speaking, less accessible to a novice student. Perhaps most importantly, few of these works are available in English.
In any event, the above is far from a complete list of the works that "broke the ground" long before the publishing of HaMafteach. HaMafteach is simply a new work, in a more modern and accesible style, in a long line of such works.