I don't think anyone read every forum on here, so trending threads across all categories would be pretty useless to most people. If you want to add trending threads, why not do the top 2 or 3 on each category? Nobody read the description of the category, so you don't need 70% of the page width to display "Hotel Deals". And nobody care about the total thread or post count for each category.. hide them? That way you will have plenty of space left on the table to display top 2 trending threads for each category.