Oh, well!
If there's say, 5 ohm between the pin and the ground left, if you connect enough power to blow up, erm, power up the pin to get more than 2.5V across the resistance, you have it on "logic 1" level. It means though, that there will be 0.5A of current going through the shrapnel, err, microcontroller, which gets dissipated (or cumulated) as heat. The 1.2 watt over 30 seconds will produce 8.5 calories, within volume of thin transistors and tracks inside the microcontroller, I'd say 0.01mm^3, raising the temperature to over 500 centigrades and possibly causing rather impressive-looking explosion.
If the resistance is high enough though, and you manage to upload the program within, say, 5 seconds, there is a small chance it will survive.