Is there a written version of what it does somewhere for the Youtube averse?
Yeah, it basically adds an option that lets you filter out items in the "New Releases" section of the home page that aren't actually new releases.
What this does is checks the items on the "New Releases" section against their actual release date.
So games like Handball Challenge 2012, D.W.A.R.F.S., and Science Girls will be removed from this section (as they're older games) and it'll make room for the games that are... you know... actually new.
There will be a checkbox similar to the "Show Downloadable Content" that you can check to show all Steam releases, giving you the same list that's currently available.
The extension will remember the combination of filters you have set and will always show your your new releases section the way you want to see it.