There are lots of additional things coming to CSS3 that don't exist in CSS2 including:
- CSS Template layout module and CSS3 Grid positioning module- creating grids with CSS
- CSS3 Text module - outline text and even create drop-shadows with CSS
- CSS3 Color module - with opacity
- Changes to the box model - including a marquee property that acts like the IE tag <marquee>
- CSS3 User Interface module - giving you new cursors, responses to actions, required fields, and even resizing elements
- Media Queries - allows you more flexibility when defining how a style sheet should be used. For instance, you could define a style sheet that is only for handheld devices that have a viewport larger than 20em.
- CSS3 Ruby module - provides support for languages that use textual ruby to annotate documents
- CSS3 Paged Media module - for even more support for paged media (paper, transparencies, etc)
- Generated content - running headers and footers, footnotes, and other content that is generated programatically, especially for paged media
- CSS3 Speech module - changes to aural CSS
