Office Depot turned in its second-quarter results yesterday, and they weren't pretty. Same-store sales fell 18% year over year, and the retailer posted an $82-million loss.Now the office-supplies chain is coming up against what is promised to be a miserable back-to-school season. Many see this period as heavily promotional with major competition from rivals like Staples and discount chains.Office Depot has already closed 114 stores in the last year, bringing its total unit count to just over 1,100. Are we likely to see more bad news for retail landlords ahead?With Circuit City and Linens 'n Things gone, it seems that were now in an environment where one specialty big-box retailer will rule the landscape in each category. Will Staples have that title before long, or can Office Depot find a way to bounce back?