These are my provisional ideas, posted here for people's gut reactions to them.
The Apocrypha of SkarosTactical - 250Options: Commander, Dreadnought, Razorback, Hunter, Vindicator, Predator, Assault, Demi-Company
Assault - 150Options: Commander, Vindicator, Predator, Mechanized
Devastator - 250Options: Commander, Dreadnought, Razorback, Hunter, Land Raider, Land Raider Terminus, Thudd Guns
Bike - 175Options: Commander, Attack Bike, Predator
Scout - 125Options: Commander, Razorback, Sniper, Land Speeder Storm
Terminator - 300
Options:Commander, Dreadnought, Vindicator, Land Raider, Land Raider Terminus
[b]Land Speeder - 175Options:Commander, Tornado/Typhoon
Land Speeder Tempest - 250 - Formation of four Land Speeder Tempests.Options: None.
Predator - 275Options: Commander, Vindicator, Hunter
Vindicator - 275Options: Commander, Hunter, Predator
Whirlwind - 300Options: Commander, Hunter
Land Raider - 350Options: Commander, Vindicator, Hunter, Land Raider Terminus
Dreadnought - 150 - Formation of four DreadnoughtsOptions: Vindicator, Dreadnought, Hunter, Predator
Options: - All standard options left out for easier consumption.
Command Vehicle - Any formation with a Captain may add a Land Raider Prometheus for 80. Any formation with a Supreme Commander may add a Damocles Command Rhino for 75 and/or a Land Raider Prometheus for 80 pts.
Assault: Add two assault bases for 75. May not be combined with the Demi-Company upgrade.
Demi-Company: Add two assault bases and two devastator bases with transport for 175. May not be combined with the Assault upgrade.
Land Raider: Add one Land Raider for 90 points.
Land Raider Terminus - Add a Land Raider Terminus to the formation for 100 points.
Mechanized - Assault marines lose the jump infantry trait, replacing it with normal infantry movement and enough Rhinos to transport them.
Predator - add one or two Predators, in any combination of Annihilators and Destructors. Annihilators cost 75 points each, while Destructors cost 65.
Thudd Guns - Any number of Devastator bases may be replaced with Thudd Gun bases at +10 points each. A Thudd Gun base has the same statistics as a Devastator Base, but replaces the Devastators missile shots with the Thudd Gun profile from the Baran Siegemasters list. The Devastators retain their Small Arms.
Imperial Support
Thunderhawk Gunship - Troop Insertion - 300
Thunderhawk Gunship - Close Air Support - 250
Thunderhawk Gunship - Saturation Bombing - 250
Plus the standard options relating to Titans and Navy. No Strike Cruiser, however - it's best not to add a layer of complication this list doesn't need. After all, if Thunderhawks are untenable, it doesn't make much sense that dropping in ballistically from orbit would be safer.
Notes:
-I'm not entirely comfortable with the tactical squad price. However, I don't Devastators shouldn't get any cheaper, and I don't think they're yet at the point where they're undercosted. If Tacticals are more expensive, Devs are better. Therefore...
-The Mechanized option for the Assault Squads is mostly there for fluff purposes. I'm sorely tempted to just remove it, and likely will.
-The Scouts have access to the Land Speeder Storm because, well, it's exactly the sort of thing that gets used in situations where Thunderhawks and Drop Pods aren't appropriate.
-Terminators are down to 300 points because they can now either walk or ride in Land Raiders - that's pretty much it.
-Land Speeders feel a little cheap at 175. Is my gut correct here?
-Land Speeder Tempests provide the list with some of the anti-air it will be lacking with the reduction in Thunderhawks, and, much like the Storm, are the sort of thing used in such situations.
-Vindicators feel a little too expensive, but they've already received one reduction from NetEA - do they need a second?
-Dreadnoughts need their own formation at this point, since otherwise they just slow everyone else down. Even so, I doubt they're going to be the most popular option.
-The Command Vehicle upgrade should likely just become a brief note in the Commander entry. I'm also a little unsure about the Damocles stats I mention here. It should provide the Prometheus ability plus a little more, but be appropriately fragile.
-The Assault option is exactly the same as in the BA list (with the obvious exception that you can't use it in Assault detachments).
-The Demi-Company option felt like a natural extension of the Assault option. It's a little unwieldly, and I don't know if anyone would ever actually use it, but hey. Also, the discount on Devastators purchased with it is intentional - a formation that big is costing you a bunch of activations.
-The Land Raider Terminus helps reduce the list's dependence on support options to kill big things and gives the list it's own Land Raider without stealing anyone else's thunder.
-Thudd Guns were available to Marines in the past (I own the models

) and help deal with the list's lack of range. I figured they're small enough to be easily moved by a Rhino and some power armored superhumans. May be too cheap, but 25 points per felt too much.
-The massive points increase on the drop version of the gunship is partly punitive, but also partly because, well, it probably should cost more than it does. After all, the pure firepower variants cost only slightly more - and carrying troops is arguably more useful...
-I'm tempted to cut support options back to 25% of points values. Marines fight fairly independently in any case, and it will help reduce the prevalence of support options in the lists slightly.
That seems to be about it. Feel free to tell me how wrong I am.