[Aeolian]

At first glance they may seem similar to each other, but the amount of content Is different.

The "New Posts" Is limited to the first 16 recent posts and keeps updating In chronological order as new posts come to hand.  The "Today's Posts" spans over a 24 hour window (hence "Today"). Essentially (for example), If there's 200 posts generated In a given day (In separate threads), the "Today's Posts" will contain far greater content than the New Posts.

I myself use new post quite frequently, it tends to show the post within a short time span (16 post as mentioned) that way if I post on those threads, I'm bound to get some conversation/discussion backwards and forth.