In the video below, Julieanne demonstrates the new Dynamic Text feature in Photoshop Beta that automatically resizes and reflows re-editable text to fill the shape of the text bounding box.
Note: In the video, I said to make sure that the text insertion point was not within the text block when adding tracking because I wanted to add tracking to all of the text. To adjust the tracking for a portion of the text block, select the text and adjust the tracking using the Character section of the Properties panel.