I have to be honest, for me, I don't think there is much that needs to be changed about this site. I think the way it is organized and put together is pretty amazing. It seems like so much work must go into how everything is integrated. But, since I see there are a lot of people who are into the equipment information thing, I had an idea that might work, although it would be a lot of work.
Posts in forums about different equipment, when you are dealing with reviews of specific products are sort of hard to organize and follow. If there was a section where different products were listed, and as many products as possible were listed, and you could enter that product and read other people's reviews and/or post your own when you have useful information about that product, it might be really helpful to people. With such a large, preexisting on line community, encouraging as many people to give reviews on products they have tested as possible would make this type of thing very helpful and would probably bring people to the site.
Now something like this already exists. Here is a link to the blades section of tabletennisdb:
http://www.tabletennisdb.com/blade/
I go there all the time, but Table Tennis Daily is so much better of a site that, if there was something like this, and we as members worked to get as much of the products reviewed as quick as possible, it would probably not only be really useful to everyone out there in the table tennis world, it would probably bring a huge number of more members to the site. However, I know this would be a huge undertaking and would make the site even more gigantic. And the site, in my opinion is by far, the best site out there on Table Tennis without any need of changes.