That Moments is mentioned so high up in the email isn't particularly reassuring...since it means they haven't launched many other initiatives of note recently. Moments as a feature is extremely disappointing given the years of interesting discoveries that Twitter has yielded algorithmically via its, well, "Discover" tab. What's on Moments looks like a half-baked newspaper front page except when you click on an item, you go to tweets about that item instead of a full story.
I don't want to pile on the project as it is new...but it should've been given more thought and design time given how much prominence "Moments" has on the interface (it is one of four main icons on the menubar)...Nearly all of the stories are hours old...e.g. "Wave of terror attacks hits Jerusalem" and "Playboy covers up"..."FedEx truck splits in two", granted, is news to me...but not something that makes Twitter unique to me.
There's so much more potential in the Trends section...OK, maybe Twitter wants to filter out potentially visually NSFW topics like #NoBraDay...but things like #MH17 and #VMworld and #ILoveYouAboutAsMuchAs...just show me an automated feed of tweets by reputable sources (rather than spambots or random kids) so I can understand why these topics are suddenly trending without having to click through the trends tag and sort through a overwhelming timeline.
edit: that said, I like all the other products...besides core Twitter, Vine and Periscope are standouts (at least, as a consumer)...I just think that "Moments" isn't worth putting into the spotlight, unless there is literally nothing else to be proud of publicly.
How? When I click on it, it just peaks at the next picture.
Moments is a glorified image slider.
Here is the "moment" for "Wave of terror attacks hits Jerusalem"...there's only about 10 tweets there:
And here's a Twitter search for "terror attacks jerusalem"
Though Fox News may not be everyone's choice of top news source, scrolling down, you'll see a great variety of tweets...maybe not as efficiently informative as the curated tweets, but I'm sure a hell of a lot more expansive and scalable.
While writing this comment, I came across this verge article  which says "For now, the tab is shown only to US Twitter users" - so if anyone else is wondering, US only. Meh.