Now, under the Discover tab users will find a new Activity stream, just below the Discover stories that we're all used to seeing on the page. It shows who your connections follow, updates to their lists, and their retweets and favorites. This makes it easy to quickly see what your friends are up to on Twitter, as well as elsewhere around the Interwebs.
With today's update, Search also boosted its powers, as it now offers suggestions for different spellings and related terms for your queries. But perhaps more importantly, the update adds autocomplete for people you follow whenever you search for someone under the Connect tab. To me, this is big because I can't tell you how many times I've begun typing out a Twitter handle only to realize that I don't remember the exact spelling.
For iOS users only, the search box in Discover also adds recent queries and a direct link to a user's profile when you're searching in Connect.
And last but not least, both the iOS and Android apps now offer push notifications for things like retweets, favorites, or when somebody new starts following you.