The $80 Super Nintendo has 21 games, but it could have hundreds of games. If the application does turn out to be for a new mini system, though, a look back shows that Nintendo filed the associated trademark applications for the Super NES Classic Edition in April of a year ago, ahead of a late September release, which would suggest that a Game Boy Classic Edition would be coming sometime next spring.
SNES on the left, NES on the right.
One poster on NeoGAF has laid out a series of instructions for hacking your SNES Classic. This means that users will no longer be restricted to the game's that come pre-loaded on the system. While there were apparently some enhancement chips in specific NES games, the SNES relied on them far more often, and some games may simply be glitchy under Nintendo's emulation method. These borders fill out the black screen that would be left out when running 4:3 games.
In many cases, players were able to add as many as 200 games into their SNES Classic units. A community devoted to SNES Classic modifications has already started up on Reddit.
Once the NES Classic was officially discontinued by Nintendo, rumors of the SNES Classic began making their rounds and eventually, those rumors (based on a trademark for the SNES' Super Famicon controller) were confirmed with the announcement of the SNES Classic. It's too early to know if the company will keep that promise, but hopefully they will. Nintendo has been plagued with supply issues since the console's launch but insists more are coming in time for the holidays.