Thanks Greg!

In IE I can create a style as follows:
<style type="text/css">
.verticaltext-ex1 {
writing-mode: tb-rl;
filter: flipv fliph;
}
.verticaltext-ex2 {
writing-mode: tb-rl;
filter: flipv flipv;
height:40px;
}
</style>

where verticaltext-ex1 generates the desired vertical text effect I'm
looking for in IE, and verticaltext-ex2 emulates what is seen in InfoPath by
using the Vertical Label control.

If I use the same style in the XSL for the view both styles are rendered the
same way as the InfoPath Vertical Label control.

If InfoPath is supposed to act the same as IE, then why the discrepancy?

I'll continue looking for a workaround (such as the text-to-graphic
conversion Greg mentioned).  Unfortunately this is something I *must* have
working for a project I'm currently working on.

Never mind -- it doesn't work in InfoPath... this is what I was thinking of:

   <div style="position:absolute;filter='progid:DXImageTransform.Microsoft.BasicImage(rotation=1)'">
       This is some vertical text
   </div>

Vertical text is supported only for foreign language support. It is not a full-blown "vertical text" feature. It is just what is available in Internet Explorer -- which does the same as what you see in InfoPath.

There is an IE default behavior (you'll need to look it up) which will dynamically convert text into a graphic and display it on the page in the vertical format you desire, and I believe (you'll need to verify it) that this is supported within InfoPath by some hand editing.