We were expecting Anthem's 1.03 patch on March 12, but according to a post from their community manager Jesse Anderson it'll be here "between 7am and 9am Central Time on March 9th" instead. Among its changes, level 30+ characters will no longer find basic white or green-rarity items, respawn timers are now based on the activity a player is in, and various improvements to stability and audio have also been made.
That's the high-level stuff but there's also a long list of more general fixes. Missions should now end when they're supposed to rather than sometimes leaving everyone in limbo until the game notices you've completed all the objectives, and you'll be able to launch an expedition from anywhere in Fort Tarsis. The base damage of various masterwork weapons has been buffed, though there's no mention of what's happening with the Defender, the starter rifle that is more powerful than anything else.
Check out the full changelist.