I personnaly come several times every day and read many posts, answer a few. I have some map project I'm working on but life doesn't let me a lot of time to do so :). There's been some projects from other people I would like to be released (delta cadimus (or something like this)'s campaign in example)
It's with that kind of theories that Arcade is filled-up with minigames and gameplay based maps. I'd liek to see good quality campaigns (like Subjection or Amber Sun / Crimson Moon). Although I play them once the story told can be very interesting and the gameplay as well.
I actually thought of creating something like this a few weeks ago. One could inspire from the Broodmothers missions that Kerrigan ordered in hots (list can be found on starcraft wikia). One is an aerial battle where a brood mother uses leviathan to fight dominion fleet above Korhal, others are about assaulting dominion world housing super weapons...
You can still use the Xel'Naga worldship tileset (Ulnar?) and add cliffs from the Immortal Forge. I find the textures pretty convincing past the fact that cliffs are man-made (although I don't remember they were in the campaign..)