Boards should have a sticky, "Currently Known Bugs"
Reading through the boards, every third thread is the same thing.
"Katarina glitch" "KAT NEEDS FIX" "Katarina Ult+Q Bug" "OMGRITOPLZFIXOMGWTFBBQ"
A simple solution:
Have a Sticky thread in the "Report a Bug" subsection, titled something like "Currently Known Bugs" or "The BBB - Bug Bulletin Board"
The OP of this thread would simply have a list of the most current bugs that have actually made it Riot's bug/QA team. This could further be broken down into things like "Top Priority" and "Soon (TM)" bugs.
This would literally take five minutes a day for one person on the team to update. I mean I assume the internal team has some kind of To Do List, so they'd just update the post to reflect that. Obviously there are a LOT of bugs that get reported, but any team like this is going to have some kind of vetting/testing process. Replicating the bug, determining the reason, etc. But once a bug gets past the "Yes, we tried it, it IS in fact a bug" then the thread could reflect that.
Just seems like a small time investment for something that could reduce a lot of redundant posting.