There is much awesomeness in this thread. My friend and I started on a design.doc for Rebellion 2 sometime in 2000. I'm going to paraphrase, as a lot of it echoes much of what's already been posted.
So here we go...
THE MAP
•Zoomable, "steerable" galaxy map, with regional borders (Deep Core, Expansion Region, Corporate Sector, etc.), much like the map shown in the Ultimate Visual Guide, or the forthcoming atlas.
•Sectors are amorphous and variably-sized, using movies and novels as inspiration.
•Hovering the mouse pointer over a sector highlights it and brings up some sort of sector status summary box.
•Catastrophic events cause the sector they happen in to flash for attention.
•Once soomed in to a sector, the system's suns are labelled. The Rebellion system of affiliation and degree of foment works great for instant intuitive sit-rep.
•Zooming into a system (I have ideas for the graphics this would involve, will post later if asked) gets similarly-labelled planets, disposition of ship activity, and so forth.
•Open battles on (or under) a planet's surface would work best if able to port in the Battlefront engine and models. Playing out campaigns in this way would extend gameplay for those who like long, epic gameplay.
CHARACTERS
•More characters, for both sides, plus unaffiliated. With top-notch art and animated interaction.
•Ability to "piggyback" after assigning to a mission, to take over direct control and leave again as desired.
•"Conference room" setting for assigning to missions -- Death Star, Home One, Massassi Briefing Room, etc. Available characters will be present. Those on missions won't be.
•Rebels recruit. Empire doesn't.
•Characters can be attached to ground or space battles (as appropriate) to augment the abilities of those present. This is also more direct than abstract.
MANAGEMENT
•Once your faction gains control of a planet/system/sector, its resources come in automatically, modified by opposing action (rebellion, interdiction, pirates, etc.).
•Trade, on all scales, is good for the economy and for morale. Although the Empire will start with control of more systems, the Rebellion will affect trade, and thus the galactic economy and morale. The Empire player will be playing to prevent this, and the Rebel player will be playing to magnify this.
•Taking a cue from dating sims will give good models for active diplomacy, negotiating with crime lords, and using Imperial fear tactics.
•Timeline is important. If gameplay starts right at the outbreak of the Clone Wars, there is already a strong division in politics and loyalties. The evolution of events and development of ships nad technology would proceed nicely from there.
GAMEPLAY
•Something dynamic and slewable for the galactic, sector, and system maps would be perfect. In my head, a bit like the Stellar Cartography room in Star Trek: Generations.
•The Homeworld engine would be awesome for large-scale space battles.
•The Battlefront engine would be great for ground battles.
•Any way to combine the zoomability and scope of Homeworld with the direct control of X-Wing: Alliance, say? Ability to climb in the cockpit of a fighter, freighter, or other minor vessel at whim?
•Tech develops automatically in the background. Jedi starfighters evolve, V-Wings get introduced,
Venators are supplemented and then succeeded by
Victorys,
Imperials, and so forth. But the player determines when and how many get built.
•Better starfighter labelling, too. The Rebellion has colour designations for their squadrons (Gold, Red, Blue, Green, Grey...), whilst the Empire has more monochrome/nasty/military names (Black, Obsidian, 181st, Emperor's Shield, etc...).
There's a lot more, but those are the broad strokes. It would be programming intensive, but basing the gameplay off of established engines would help a bit. THe trick would be getting them to flow one into another smoothly. Blu-Ray DVD-ROM would pretty much be a necessary format. But I think the ability to change your perspective from the entire galaxy all the way down to a single Stormtrooper is key. As well as unalterable events, like Palpatine declaring himself Emperor and issuing Order 66 or the Yuuzhong Vong invasion. For things like Order 66, a random-number subroutine to determine if any Jedi survive, and which ones, and where they hide -- maybe stumble across them later in the game, maybe not, maybe source of missions ("Help me, Obi-Wan Kenobi. You're my only hope...").
One thing I loved about the first game was the ability to name your ships. I had all my Star Destroyers, Interdictors, and all twenty SSDs named after ships from the movies, books, and games. It was lovely. And I named my Death Star "Harmless Ore-Processing Station". But I think the AI should have more in its databanks for auto-assigning names than "Star Detroyer 15".
I would also like to have something in the game for matching commanders to their ships. Maybe automatically, maybe not. Maybe a bonus to commander and/or ship when you do it manually... Not clearly thought out yet, but the germ of the idea is there.
I'll let y'all pick apart what I've posted so far.
--Jonah