Is Vegas text, vector graphics?
 

I'm trying to avoid After Effects, but don't want any jaggies. Thanks.

Well... sort of. If you make the font size larger, it will enlarge without jaggies as fonts are vector. However, if you use Track Motion or Pan/Crop to enlarge them, you'll get jaggies because now you're enlarging the video frame. One common trick is to make the Frame Size as twice the project size which also helps reduce jaggies.

Of course, Vegas Pro 8 no includes the ProType Titler as well which you can use instead.

Assuming you're talking about the original text tool, no, it isn't.
I'm not sure about Pro Titler as I haven't used it yet but my guess would be no to it as well.
Having said that, one trick (for the original titler) is to make your text at least double screen resolution when you create it.
That is, in the upper left corner of the text box is the h & V size boxes.
For an SD project, change these to 1440 x 960.
It does make a difference in the quality.
Unfortunately you have to do this each and every time you create a new text event as you can't save this as a preset :-(