Very nice idea (really) going well.
I have some suggestions for improvments:
1. Text at start takes too long, put it as credits at end
2. The cursor (even with delete :-) is nice so dont centre the text which ruins the illusion...I dont expect my cursor to bounce around.
3. Use another voice other than Microsoft Sam - isnt there at least one other default voice? If not maybe you can add one. Microsoft Sam is getting a bit overused.
All that said, I have to say, again what a great idea this is (wish I'd thought of it). The best of luck with the project.