Right now, only Adobe products can use the full range of Open Type
facilities, and even they don't at the same level. My understanding
is that InDesign is the most complete. Illustrator has the "glyph
palette" that eases access to the full glyph complement. It's
possible, but more difficult, in Photoshop.
Microsoft's Unicode and Opentype support is almost random across
applications. CharacterMap seems to work well with the extended glyphs
for some fonts but not with some others.
If someone has better information than I've offered, PLEASE feel free
to correct me!