ArialUnicodeMS is sort of the mother lode of fonts. It's a font intended to support the Unicode character set, which is basically the world.
But it's a BIG font file, and that has presented some problems. Adobe Acrobat Distiller can't handle a font with more than 16,000 characters. And for other technical reasons, the Ghostscript PDF converter delivered with XPP is also unable to handle this font the way XPP presents it in the PostScript file.
The good news is that the XPP Direct to PDF feature, first introduced in XPP 9.0, can handle ArialUnicode. XPP's direct to PDF feature does not first create a PostScript file and then distill it, hence the term "direct to PDF". Before this, the only options were to first create the PostScript file and then distill it using Acrobat or Ghostscript. Although a two-step process, XPP made it relatively seamless, and you can continue to use it as always.
Initially, in XPP 9.0, when using the Direct to PDF feature, the resulting PDF did not look right. This was due to a documented product limitation in which XPP did not support Truetype fonts without PostScript names (e.g. ArialUnicodeMS.ttf). That was addressed in XPP 9.1, and the fix will be back-fitted to XPP 9.0.4 (service pack 4, which does not yet have a release date at this posting).
Some basic testing indicates that the resulting PDF should also have searchable and selectable text.
Why use ArialUnicode? I'm interested in your comments, but my thought is that it would serve well as a "secondary FAST" in XPP. A secondary FAST is a backup to your primary font. If your data contains characters for symbols, accents, and characters from other languages, these characters should display properly without having to change to another font family. That is, it will do so if your font variant spec is set up appropriately. This is a good thing because then you don't have to use multiple symbol fonts or hunt around for a font that contains your character. Oh, and by the way, if you ARE changing in and out of a font family to render that certain symbol character, you shouldn't need to with a properly set up secondary font environment!