Do they have the monetisation scheme in place already? Can you have a decent session without paying (you were supposed to "pay for fuel", right?)? Anything more?
No, during the beta fuel was unlimited. Even after release, fuel will regenerate at a set rate (every four hours).
Visually, it's similar to Assault Horizon, but it doesn't suffer from the same problems as its predecessor. Removing DFM allows you to appreciate the destruction more when it isn't ostentatious and in your face. Gameplay has been overhauled. As I mentioned before, DFM/ASM is gone, and skills have been replaced by Data Links, which are abilities (faster reload, missile power, etc.) that help your entire team. Aircraft are unlocked on a tiered system, roughly corresponding to NATO and Warsaw Pact arsenals. You can level up aircraft to unlock new special weapons and modify their stats with parts.
So far, only two campaign missions are playable. There are 3 or 4 co-op missions that alternate, as well.
The beta went offline on Friday for an unknown reason. The splash screen on the PS3 says it will be restored at an undetermined date, while Project Ace's Twitter says they hope to have it back up next week. No word on what could have caused it, but it must have been a major issue if the game has been completely pulled and is not just down for maintenance. The only major bug I noticed during the beta was that occasionally (maybe 1 out of 20 chance), the mission would end immediately after it started, awarding a random player MVP and setting everyone's score to zero. Not a significant problem in the beta where fuel supply is infinite, but upon release, that could have been a major problem.