Question about customizing/theming iOS

I have iPhone5 with iOS 6.1.4. I've been holding out for a jailbreak for THIS version of iOS because of reports that winter board won't work with iOS 7.x.x. However, in this article it says the following: "Most jailbreak apps rely on MobileSubstrate to tweak system functions, so this could make the first version of evasi0n disappointing for many people who would want to change the way iOS 7 looks or functions. Hopefully, a fix is released soon."

Assuming they come out with a fix for the mobile substrate compatibility issue, does that mean it would be possible to theme iOS 7 without winter board? And if so what exactly can you change? Or, does that mean something else and it's just completely impossible to theme iOS without winter board?