That big blank space is because Delta has removed one of the original columns of information that used to be included in all itinerary..."Flight Segment Status".

To the left of the "Upgrade Status" column was the "Flight Segment Status" which always showed 'confirmed' for me though I'm sure it could say something else in certain situations.

Possibly this field is coming back or possibly not. EDIT: Delta now puts your segment status underneath the flight number in the far left column. Mine shows the flight number and then "reservation: confirmed".

Edit 2: I also notice that gate assignments are displayed for the departure & arrival of your flight. Guessing Delta now pulls this data when you open your reservation.

The "Your seating" link does absolutely nothing but I'm guessing it's there in case you have a lengthy itinerary and your seat assignments scroll off the screen. This link probably takes you right there...maybe?!

-RM