I noticed (what I think is) a slight problem with WYSIWYG fonts in 2.6.1 yesterday. Looking down the list I saw that some fonts do not show a name (things like Mathematica fonts) but was not too concerned as they are obscure and rarely if ever used.
I did notice that Zapfino down at the bottom of the list was poorly rendered due to the 'swirliness' of the font and there was no way to guess the name. More importantly for me, it could not be selected from the font menu by typing Z-A-P-F etc where other fonts could.
Hope this makes sense.