The bottom line is that the average user will not notice any differences between the 2 versions of PowerPoint. Some positives:
- The application has slightly more Mac fee to it
- I like the organized way fonts weights are grouped together.
- The integration with Aperture, a photo organizer is very good. If you buy images from iStockPhoto, somehow a lot of keywords are saved with the file. PowerPoint 2011 integrates seamlessly with Aperture, making the full library of images on your hard drive searchable by keyword.
- The selection pane, a great tool construct complex layered diagrams is missing. (An earlier post about the selection pane here)
- Toolbar customization could make PowerPoint 2011 crash. Especially, do not try to drag the straight arrow connector into your top toolbar. If your software has been corrupted, see this Microsoft post about how to fix things. [UPDATE, THE RELEASE OF SP 1 MIGHT HAVE SOLVED THIS ISSUE]
- Whenever you try to move or resize an object very close to the static guides, PowerPoint will decide to move the static guide, not the object, and staying on the subject of static guides: you cannot space the interval at which you want to set static guides.
- Color rendering can be a bit off. When give the text and its background shape the same color, you can still read the text on the Mac, but not on the PC. PowerPoint for the Mac handles colors for shapes and text differently.
- PowerPoint for Mac cannot embed custom fonts (PowerPoint Ninja explains what this is)
- You cannot insert vector shapes in the Mac version of PowerPoint (see here why this is can be useful), so if you want to adjust the color of a vector diagram, you have to do it in Illustrator and import the illustration as a picture into PowerPoint.
The bottom line: professional presentation designers should check their end product on both machines before shipping it to the client. For the rest of the users (99.9%), people probably will not notice the difference.