Fan Casting What If The Tenth Doctor regenerated in Journey's End

The Stolen Earth will still continue as usual but only change I will make is to have I'm regenerating to The Tenth Doctor's last line before starting to burst into regenerative energy. Then as we head to Journey's End ( instead of putting the rest of the regenerative energy into the spare hand ) The Regeneration continues and then when the process was completed we witnessed the arrival of The Eleventh Doctor ( still played By Matt Smith ) he starts to regain control of himself after regenerated