Add the option to select multiple Subreddits to post to. Right now you can only select one for each post.
Customize each subreddit submition individually: title, first comment (when implemented), date and hour (with recommended optimal times), media (customize images and videos individually) and flairs.
Also, adding "templates" so you can save all these basic configurations is a plus.

Postpone does all of this very decently, but I think Vistasocial has huge potential and can draw tons of new users that post on Reddit.