Makes sense to me. Crazy mathematicians have uses for all those letters in proofs!

(I know, I was one in undergrad before changing career direction...)

Yes, great link! Thank you, John.
Is there a clever way to access all these characters? I mean, other than via the glyph palette?

The ‘new Fraktur’ is actually a variation on Wittenberger. “Based on Schelter & Giesecke’s School Fraktur which was in turn based on type favored by early 16th century printers in Wittenberg” — Adobe.
Especially the uppercase ‘K’ has been altered – I assume to distinguish it more from the ‘R’. While I’m not a fan of the original Wittenberger ‘K’ either, I must say that the new ‘K’ is my least favourite character in Cambria’s blackletter. Its head looks stretched.

The script letters are absolutely lovely! I wonder what their source is. Similar charm as that of Kursivschrift or Fiona.

It seems Cambria is the new Lucida, in terms of style variety – and all in one single font.

Most of the mathalphanumeric characters were designed by Cambria's original designer, Jelle Bosma at Monotype. The 'ssty' optically adjusted scaleable variants used by the MS math handler for super- and subscript variants were made by Ross Mills at Tiro, as were the new math monospace letters that will be included in the new Windows 7 version (along with a lot of other non-math stuff that I made, with some help from David Brezina, including polytonic Greek and massively extended Latin and Cyrillic support).

The thing to note about the math alphanumerics is that they are limited character sets, generally no more than A-Z and a-z. They are encoded using Unicode Plane 1 codepoints for math alphanumerics, and they are also spaced more for use as math symbols than for regular text.