A nice addition to Apple's e-mail application Mail is the introduction of HTML-based templates that can used to send elegant-looking e-mails. Unlike those in Apple's iWeb application, the templates in the next version of Mail are easily accessible, so if a user wants to create his own stationery template, doing so is a snap. The new Mail app also has some nifty context-sensitive hooks into iCal.
iChat
Ahh, iChat, my favorite underappreciated application. In past Mac OS revisions, Apple added audio and video chat (Panther), 10-way audio conferencing and four-way videoconferencing (Tiger), and now the company has added an API called iChat theatre. It allows the application to be used as a professional presentation tool, meaning Keynote, iPhoto and Quicktime output can be piped directly into an iChat video stream. The quality was excellent, probably leveraging Core Animation and compressed in h.264 for high-quality video over low bandwidth. This allows iChat to be used in myriad ways, by film companies viewing dailies, for instance, or by anyone doing a sales presentation. It takes the application to a whole new level.
In addition, a sophisticated chroma key algorithm was added so that a user can do a snapshot of the background he is chatting in front of, and it will remove the background and key in a background image or video of the user's choice. For corporate presentations, podcasts or just plain having fun, this is a great feature.