Boris Red, and After effects can, but seems like there is a company that makes title software for vegas that probably does it for a lot less cash,, maybe search title software on the forum,, I forget the name of the company.
There was a video I saw somewhere in a sample VEG file that did this. If memory serves, what they did was use a mask and keyframing to "unhide" the text via keyframing.
I think this video was a sample VEG from Sony that was included maybe with Vegas 4? Can't remember.