Funny you should mention this, I was at a family reunion and my uncle created a powerpoint show which featured a lot of family history, videos, pictures and music which played along. It had an opening sequence much like the beginning of Star Wars, along with the whole episode theme to it which coincided with different times in my families life. It was very special. I'll see if I can get some info on that for you.
There's a Word Art button on the drawing toolbar (or Insert | Picture> | Word Art... from the menu). Word Art has an option (3<sup>rd</sup> column, 4<sup>th</sup> row for me) that approximates that text style. I think you could use custom animation and apply an entrance, movement or exit effect that would get you there. I just briefly played with an exit animation, placing the textbox below the slide and customized the timing to 8 seconds and doing a "fly out" exit out the top. It doesn't shrink off into the distance. I think you'd need to create a bunch of boxes and control their position, visibility & font with a macro if you wanted to actually make the text grow smaller and smaller as it scrolled up the slide.