@doblocruiser here's a supposed mined data leak. http://www.forbes.com/sites/insertc...s-the-games-total-mission-count/#56e7d57a7716
Seems to have 26 missions in the main game. I imagine it will be Destiny like where you can replay those missions on harder difficulty for better loot. So I'd guess you'd still get plenty of entertainment out of playing solo, if you like the loot grind type of games?
I read that a Survival mode is due this summer so that should be pretty cool to!