This update adds a second scenario that can be seeded in a nebula, beginning the move towards much-needed variety for the champions' "offroad" exploits. This scenario introduces three new splinter factions (one zenith, one neinzul, one spire) with 16 units between them. A couple new champion hull types are possible as rewards (no, not larger than the ones previously available, but we're getting to that), and 5 new scenario-unlocked module lines for champions are available. Not all champions can use all modules, but it won't give you a module line you can't use at all.
Many long-time members of the Arcen community will appreciate one particular fix: the bug that caused a "ghost" of a unit's build queue to sometimes draw just a little below it is now gone. Finding the greater-than sign that needed to be greater-than-or-equal-to took 3 hours, so be happy! ;)
There's also a variety of other bugfixes and some balance changes (notably to part of the AI's reinforcements logic, since reinforcements have been so low lately).
Update: 5.059 hotfix is out to fix a bug in the 5.058 reinforcements changes that caused AI reinforcements to go Stark! Raving! Mad! Thanks for letting us know about that one, though the AI looks sad now.
This is a standard update that you can download through the in-game updater itself, if you already have 4.000 or later. When you launch the game, you'll see the notice of the update having been found if you're connected to the Internet at the time. If you don't have 4.000 or later, you can download that here.