We can definitely kill all three of the bosses mentioned above. Getting through normal Mannoroth should only take an hour or so. Heroic Iskar will take less than an hour after the work we've already done, and that would leave us a fair amount of time to possibly get Socrethar, also. Or we can just continue on and kill Archimonde. We were close last week, we will get him this week.
Progressing on heroic brings good gear, progressing on normal Archimonde brings class trinkets. You decide!