The exploit in question, developed by iOS security researcher pod2g and the iPhone Dev Team, requires the use of an Apple Developer account in order to inject the untethered files into the iPhone 4S and iPad 2. In other words, it would appear that millions of prospective jailbreakers would need to purchase Apple’s annual $99 Developer subscription in order to even have access to this exploit.
Nevertheless, pod2g and the iPhone Dev Team have ruled out this possibility, citing inaccessibility issues to the population at large. Both parties are working hard to find a free publicly distributable exploit that can be used to remount the system partition read/write and help in configuring Corona’s untethered jailbreak files at the appropriate places in the operating system.
In the meantime, updates on the status of this workaround can be found on pod2g’s Twitter account here.