A couple of suggestions to improve game play as I agree the whole base capture thing is getting kind of stale.
One day a week (other than TT) make it axis vs allies in the MA. One side U.S., Brits & USSR, the other side German, Japs and Italians. You can only use the planes & vehicles of your country. Or make it a 3 way, Japs on one side, Germans on another and U.S. on the third side. Rotate countries every week so everyone gets a chance to be a Jap, a Kraut or a Yank. And like TT, have only 1 main arena for that day.
Here's another suggestion. Recreate actual battles in the MA rather than in Special Events. How about a Battle of the Bulge in the MA with 400 participants? I'm not an avid GV'er, but 400 guys in a massive tank battle would definitely interest me. Or recreate the Battle of Midway in the MA. Again, pick one day of the week for this event, say Thursdays, and run the event on this day.
It doesn't have to be a permanent thing. We can try this stuff out for a couple of weeks and see if everyone likes it. Personally, I look forward to Titanic Tuesday but other than that most nights in the MA are kind of boring.