I don't think the Arc will fail, but I can't imagine that 3rd party developers are going to go crazy releasing good games.
Alot of games such as Madden '11 will get Arc Support, but they will not be exclusive Arc games. Not many 3rd party publishers will want to try to sell a game to a fractured user-base. Arc, by definition, is a niche fanbase because it was released mid-console.
The only way Arc will be a success is if Sony releases a plethora of good 1st party games. The only reason the Wii has been a success is because Nintendo kept releasing good games. The 3rd party developers haven't been motivated enough on the Wii to release many quality games-- I think it will be even worse with Arc since the Arc user-base will be much, much smaller than Wii.
Other than that, expect to see lots of cross-ports between Wii and Arc. There might be a couple big-budget games for Arc such as a Star Wars light-saber game, but there can only be so many games advertised at a niche target.
Arc has a major uphill battle to be successful, especially gauging on the limited success of the Eye Toy.
Most anticipated games of 2011:
Uncharted 3,Legend of Zelda: Skyward Sword, Rocksmith
Modern Warfare 3, Super Mario 3D