Just making a quick prediction:
By May 1, 2011, no more than two of the current "top 20" games will differ.
The new user experience: Try out the 20 games... visit every once in awhile... see that nothing has changed... go back to Kongregate, ArmorGames, etc...
A quick suggestion:
Make a temporal based rank as well. Dedicate the top five slots on both columns to be "Newest Games" (naturally, they aren't rips or fangames and would be easily determined by a moderator), and "Hottest Games of the Month". Hottest can be determined by some kind of Newgrounds/Kongregate criteria or simple "view count"-like value. Side note: make your ranking formula either public or simple.
The "top 10" historical should occupy the bottom half of the page.
This will keep your front page fresh and encourage people to develop new and original games on BYOND.