Yeah but you kinda need a guide like that with the Hadoop ecosystem. There are so many projects in common usage, each with their own niche but with some overlap, vendor spin, etc... and it can all change so quickly. Newcomers really need a "field guide" to just explain what's what at a high level.

Yep, my team has started on the "slightly more data than our RDBMS can handle" route, and I've had the whole Hadoop-is-a-ecosystem thing-not-a-single-technology discussion multiple times with developers and product managers alike.