I haven't got a clue how feasible this type of thing would be, not being all that familiar with ARMA, but some sort of rendition of Battlefield's Wake Island would excellent I reckon, with emphasis on the helicopter-assault side of things.
I realise it's in a similar vein to the Island Attack mission, but anyway, here goes. I would picture it as a small forward base for the US, perhaps on a small island rather than a carrier for the sake of simplicity. They would then be provided with a small helicopter force to get across to the enemy island and pick which positions to assault, from a choice of the main enemy base, or the far smaller northern and southern outposts, each with a single narrow route to the main base. The aim would be for the OPFOR to hold the main base at all costs - if captured by the Americans, the mission is over. However, if it could be held for a reasonable length of time, until reinforcements could be called in, the OPFOR would have succeeded.
The interesting thing would be which strategy each team uses - for the attacking team, if they just flew a Blackhawk straight into the main base they'd be shot out of the sky, so they have two options. They could land near the southern/northern outposts (focussing on taking either one or both of them) and mount a sustained assault until they capture them, then moving their ground troops towards the main base with the aim of capturing that as well - or perhaps (I have no idea whether this is possible) they would be able to draw the OPFOR into a ground battle at one of the outposts whilst a 2 man squad sneaked into the main base, either destroying the AA, in which case the entire force could be dropped directly into the main base, or just quietly destroying other assets and taking control of the point.
Obviously it's got a lot of similarities to Zak's mission, but the crucial aspect in this mission that I enjoy is coming in by air and trying to secure a position - if somebody decides to go in on their own, they've got no chance, but if you get a good team of four down with a diversionary attack on another location, they should theoretically be able to hold off the attacks from the entrenched enemy, and gain a foothold on the island, from which they can work towards the main base and ultimately take control of it.
I think the crucial aspect is picking a suitable location - if the area is too large, then dropping forces in will be very easy, they'll be miles away from the action and have no problem getting set up, and it becomes a typical ground-assault map. If the area is the right size though, they'll have to take a lot of care over when, where and how they land, and obviously the respawning would have to be thought through as well. If the US just drop a spawn point in the trees 200 yards outside of one of the outposts as soon as they make first touchdown, then it defeats the object of the helicopter assault side of things.
I know it probably wouldn't work in ARMA/sucks/etc, but it's more just a collection of ideas than a mission set in stone... the helicopter assault is the main thing, I'm imagining a close contact ground landing against entrenched enemy soldiers, similar to that of Operation Barras in 2000. Anyway, feel free to maul it, just thought I might as well jot down my ideas