The browser ballot was conceived by Microsoft and the European Commission, with input from the other browser makers, Opera, Mozilla, and Google (I'm not sure if Apple participated in any meaningful way). The remaining seven browsers currently on the ballot, AvantBrowser, Flock, K-Meleon, GreenBrowser, Maxthon, Sleipnir, and SlimBrowser, didn't know they'd be on the ballot until only very recently.
They were not involved in the design process of the ballot screen, and this stings. Six of the seven "secondary" browsers (a representative of K-Meleon couldn't be located) are now complaining that there isn't enough visual indication that there are browsers to choose from to the right of the big five, and have sent an urgent petition to the EC to address this issue.
"Please know that we are not suggesting any major reevaluation or redesign of the Choice Screen at this time," the petition reads, "We are only requesting the simple addition of *any* text or design element, that would indicate to an average user that there are choices 'to the right of the visible screen'."
The Secondary Six (sounds like a band of superheroes, doesn't it?) state that a mere scrollbar isn't enough, since horizontal scrolling is uncommon and not particularly liked by users. As such, they suggest including some sort of an indication that more is to be found 'to the right'.
On a related note, Opera says they are already seeing an increase in downloads of the Opera browser since the ballot rollout. "Since the browser choice screen rollout, Opera downloads have more than tripled in major European countries, such as Belgium, France, Spain, Poland and the UK," said Rolf Assev, Opera's chief strategy officer. Of course, this could also be related to the fact Opera released a new version.