The answer; not a whole lot. Some abilities were changed, Eldar holofields got a rework and we now have melta torpedoes (same as normal torpedoes, save that they cause fires rather than deal damage and lack the armour-piercing capabilities of the normal torpedoes). The custom game mode is, sadly, not the sandbox-eque skirmish mode I was hoping for; you pick either your single or multiplayer profiles or one randomly-generated by the computer and it is limited to battles against the AI so the game does lack a way to challenge your friends to a game.
Now, that being said, the developers released their development roadmap about a week after launch and some of the stuff in there is looking somewhat promising. The full roadmap can be found on their official forums here but here are some of the highlights:
- Custom online games against friends - when I said the game lacked a way to challenge your friends, that's only going to be for a few more weeks (barring delays that have been announced since I typed this up, of course)
- Pre-set behaviours - you might've seen me setting options for each ship at the start of the battle; things like engagement range and whether to engage in broadside attacks or prow engagement. This will let us set those options while in the fleet management screen before even searching for a match.
- The Tau - the second DLC fleet included in the early adopters bonus has been announced. No word on when they'll be ready, but so long as you either pre-ordered the game or buy it within the first two months after launch (so sometime before late-June) you'll get both this fleet and the Space Marines for free.
- Fleet Colour - they've been clear since AngryJoe's preview of the game that the fleet painter wouldn't be ready for launch. There's still no word on when it will be ready, but it is coming.
The campaign is in though I haven't gotten too far into it yet (procrastination, distraction and getting very frustrated trying to complete this one mission - dear god do I hate Data Recovery when you can only field 300 points worth of ships) but everything I have seen of it makes it really feel like a 40k game. The tone and atmosphere is all there, the look of the different characters and starship interiors is true to the classic artwork. The voice-acting deserves a mention as well, any 40k game with a story to it will rely on its voice actors to bring just the right level of hamminess to the performance without going overboard.
I was originally going to do this up as a video, but I felt like it wasn't worth doing all the recording and editing. Plus with the way my allergies have been acting up lately, half of the voice over recording would end up on the cutting room floor due to me coughing up a lung or six.