As we jump from date to date trying to figure out when exactly this phone will come out, there has never really been a firm “reason” for the Thunderbolt’s launch being put off. Many figured it was due to the debut of the iPhone 4, and later that turned into the debut of the Motorola XOOM, but now Engadget’s suggesting the problem is more technical than it is strategical: the phone apparently has horrible battery life.
Another independent source mentioned to them that the bad battery life is due to a bug in the Thunderbolt’s firmware causing signal issues. Whatever it is, they said that a fix is in the works. Hopefully this is the last road bump in a sea of them as this has reportedly been the device’s sixth delay.