I have a regular PS/2 two-button mouse on my test system, and running Pinstripe text mode install doesn't give me a mouse selection screen at all. Previous betas did. Is this a bug or a feature? (ie is there some weirdness and a serious bug or is there just some sort of a newer, really smart mouse auto-detection in Pinstripe?) I'm able to move the mouse in the X test start ("can you see this message") and in the first few moments on a newly started X on the installed system, but X hangs shortly after I try to move a window. Don't know if that problem is related, but I entered that X problem in bug 15089.
Your mouse was probed automatically so you didn't get prompted.