Bad news for those who use MathType as an equation typesetter in Indesign on the Mac...
MathType uses some kind of artificial "slanting" of the Symbol font to put Greek letters in "italics," and this worked in previous versions of Indesign CS4. However, Indesign CS5 doesn't recognize the slanted symbol font, and replaces it with a default sans-serif font in the placed eps files, so your Greek characters in MathType become Roman letters once placed.
This can be solved -- at the expense of typographic accuracy -- by changing MathType's preferences to use non-italic Greek letters. What would be ideal would be if MathType allowed the use of the lovely modern fonts that include Greek characters (Minion Pro, Garamond Premiere Pro, Adobe Caslon Pro, Myriad Pro, and heck, even a number of the recent fonts from Microsoft). I found that the Windows version of MathType does allow these characters to be accessed, it's us poor Mac users for a change who are left with crippled typography.
I have written to MathType, but I suspect they're waiting for the next issue of Microsoft Office, since MathType relies heavily on scripting features that were dropped in Microsoft Word 2008 (for the Mac), but which have been promised to return in the next edition.
So, if italic Greek letters are important to your typesetting, you may want to hold off on Indesign CS5 for a while.