The Fall Of Reach - HALO 2 Player Starter Box

Start stoking up the engine, boys. The hype train is leaving the station!

UNSC for the win!

Humanity could be:
UNSC - generic, as they are now,
ONI - very small numbers, rely on evasion, sabotage and stealth. Could possibly mine areas in advance with SHIVA nukes, and get some sort of scanner system to allow one vessel to forego firing to boost attacks against a selected model. Also Spartan IIIs, yo,
Insurrectionists - even worse equipped than UNSC and no Spartans, but cheap as crap with a few special rules. Nukes over MAC weaponry and the like, get bombers that can carry tac nukes and the like as an upgrade,

Then you'd have:
Sangheili fleets - basically the Covenant as they are now,
Jiralhanae fleets - much more oriented around boarding and close quarters fighting, but less technologically advanced, so lower Shields etc,
Kig'yar fleets - piratical fleets that use a lot of boarding tactics, maybe cool kit to stun vessels, etc. Get hangars with slews of fighters/bombers as well, given their preference for small attack craft,

Didact Prometheans - greater range on boarding due to teleportation, absolutely tiny numbers of vessels but devastating firepower and strength. No fighter or bomber complements to speak of,

Librarian Sentinels - Fairly standard, but Elements can combine fire or shields to far greater effect if they're close enough. Possibly have a larger Element size, so say 10 rather than 6, with buffs dependent on the Element size. Think Ghosts of Onyx with the Sentinels combining together into vessels capable of annihilating Covenant Battle Cruisers with ease. Possibly even have the ability for a large group of fighters to form up into a Frigate or something, to represent them coming together, then allow the player to break them up at the beginning of their Movement phase, making them extremely flexible as they collect into Cruisers one turn, then dissolve into fighters and frigates the next,

Flood - whatever everyone else is running, possible hodge-podge of stuff. Boarding should be very lethal, and the possibility of a Gravemind on the Capital ship to improve Firepower or something would be cool. Hive Mind effect could be an interesting rule to consider, how to translate it to the game I can't think of right now. Perhaps it allows units to fire through asteroid fields and such as if they weren't there, provided a Gravemind vessel has clear LoS to it? Their vessels should be a little battle damaged and weakened, but robust enough to close to Boarding range so they can infect other vessels, (perhaps have that replace the explosion result?)

I think there's lots they could do in terms of flavourful variation in factions. Just gotta hope they do it!