Seth Killian, Capcom Community Manager and face of all things Street Fighter in North America, chatted with Gamasutra to expound upon some of the Gem System's intricacies and the design philosophy behind it. First and foremost, Killian stressed that the system has been part of SFxT's design philosophy for years, and that it represents the proverbial "nerd feather" that intrigues analytical theorycraft-style gamers.
He also addressed concerns that the Gem System would provide an unprecedented boost in artificial skill to unskilled players, saying that there's no combination of gems that would allow an unskilled fighter to triumph over someone who knows what they're doing, as each gem has its own specific activation requirement. Since gems aren't always "on," players will have to rely on their own abilities to meet those requirements and enable the ability, supposedly removing the potential for scrubs to earn top honors.
Most players, however, are not concerned with the Gem System's balance implications so much as they are the idea of gem exclusivity; Capcom has already announced that certain gems (and their related abilities) will only be available in specific pre-order or collector's edition packages. Gems may even be monetized as DLC, though Killian was unable to address those concerns beyond stating that Capcom is still "sort of figuring that stuff out," and reassured that no player would be able to buy their way into an advantage.
Balancing a fighting game is, well, a difficult act to begin with, and by adding thousands of potential variations to dozens of characters' abilities, we're worried that Capcom's attempt at creating an expressive customizable fighting environment will inadvertently result in an extremely rigid and defined tiered experience like Marvel vs. Capcom 2. As is the way with fighters, it will take months of post-release analysis and technology research by dedicated fighters before any of this will be settled; all we can do in the meantime is wait, and debate.