A bit presumptive but many things are out there at this point that we can talk about it without Vultures, Venators, and Vendettas(I just noticed after almost ten years of playing Elysians all of our vehicles start with V).
Things we can safely assume:
Missile launchers will be our heaviest weapon.
Mortars and heavy bolters will be there.
Deep strike on basic troops and maybe our Valkyries as well
Not sure aside from deep strike what our special rules will be. Likely something to mitigate Battleshock.
Now assuming the list stays relatively intact, what are people's plans?
After playing a fairly large multiplayer game(using my alphas) and seeing what different armies can do now I have kinda gotten a direction for my Elysians with the assumptions above. Our flyers are going to get their butts kicked. That -1 modifier for hard to hit is nothing for MEQ armies with a zillion shots, that and flamers can hit us like its cool. I wiped Drago and 2 paladins off the board in one round of shooting with rapid firing combi-plasmas taking the -1 to hit to fire both weapons and still taking them down.
Aside from special rules we can actually almost play our Elysians now. Troops, all the valks we want, all the weapon squads we want, storm troopers, vet squads, etc. Your aircraft are going to want to keep moving. You will take a pounding if you stay in the same area. Also means you will only get two shots at a specific target before moving out of range. I haven't noticed a rule yet that says flyers don't get cover so if you reach a board edge and have to fly off, just switch to hover but try and position yourself behind cover.
Heavy weapon teams
Heavy bolters and mortars are dirt cheap. Missiles a bit more. This matters as they are cheap slot fillers on a brigade while still being stupidly effective. Missile launchers are one of the best utility weapons in the game now causing d6 damage and at the same time doing d6 shots with frags. 3-18 shots. Very worth it. Mortars are the cheapest heavy weapon choice we have, I think at something like 27 points for three. It will put some wounds on something. Might not kill more than a marine, maybe two if lucky but 2 would pay for the whole squad and they can do it without coming into LOS. Heavy Bolters are just good general dakka without breaking the bank. I expect to see a bunch of them and autocannons in normal IG lists. After witnessing a monolith die to lasguns, mass dakka isn't just about overwhelming terminators anymore. Plus a heavy bolter being 5 strength with a -1 to armor saves, means most normal non heavy vehicles will be wounded on a 5+. I know heavy weapons squads weren't used often in the last few editions, but now I think with their relatively low cost, will be invaluable. In my army I plan on at least 2 missile, 2 mortar, and a heavy bolter team in most normal sized lists.
But what about Vendettas? I see vendettas approaching land raider costs. I haven't seen a data sheet or heard anyone talk about having seen them but a barebones Valk is 130, a twinlinked lascannon is I think 50 if I remember right. I have heard they are pointing out vehicles in the FW books very conservatively so we are safely looking at upwards of 300 points for a vendetta. It will be the big boy in our armies. Really hoping they up the BS to account for its super high cost.
Valkyries- Our basic bird. I think its one of the best transports in the game allowing a nasty meltagun range alpha strike on enemy vehicles. It hasn't been FAQ'd yet to say it doesn't. Maybe GW threw us a bone for once intentionally. So what do we put in here? I am thinking either vet, command or special weapon squads and more likely a mix of the latter two. A pair of command squads and a SWS all with meltas. Its borderline broken with 9 meltaguns. Yeah they will die stupidly quick to the opponent's other forces, but very little, outside of broken necron vehicles who will ignore half of the damage, will survive. I haven't run the numbers but a quick run through the numbers 6 will put 21 wounds on most vehicles. Better if you skip the SWS and add a commander with orders.
Really not sure what to do with these guys right now. I haven't used them or seen them used. I know my old deep strike and use heavy flamers thing isn't going to work anymore for obvious reasons. Since we do have non-scatter DS(or will) then perhaps multi-meltas might come back in vogue. Yeah its a one shot weapon which is never good for BS4+ but a pair of them have a 50/50 chance to hit and you can DS into their short range. Until we get DS I am not sure what to do with them.
Vets- Another good group of riders for a Valkyrie with their BS 3+ and 3 special weapons and heavy flamer(assuming we keep it in the new list). Quite pricy though, especially vs Storm Troopers who get a lot more bang for the buck.
Storm troopers- The bread and butter troop of normal IG this edition. Its an autoinclude for most people. They deepstrike on their own, carry 2-4 special weapons, 4+ save, have their own officer and 4 special weapon command squads. Kind of hard not to like these guys. They have been covered extensively elsewhere though and their use doesn't change here. Unless of course FW uses common sense and makes them elites in an elysian list which is what I think they will do.
Troops- Your normal cool looking guys which was a good chunk of why we built these armies. I don't think anything will change in their usage. I am tempted to put a plasma pistol on the sergeant and use a special weapon of some sort, but keep them cheap and plentiful. I doubt we will see FW return them to a platoon style formation, I hope they don't actually since I like the new/old system of guard organization where each squad is a slot.