January is an important month for Macintosh users. MacWorld Expo takes place every year in San Francisco and we usually see a lot of new software and hardware. The MacBook Air is a wonderful new subnotebook perfect for successful scientists with many talks to give and enough money to spend.
But Microsoft Office 2008 for Mac is probably the most important new product from a scientists perspective. If you live in the U.S., you can buy Office right now, us international users will have to wait a few weeks. Office 2008 runs natively (i.e. much faster) on Intel Macs, so everybody with those newer Macs wants to upgrade for that reason alone. Powerpoint and Excel are important, but Microsoft Word is the application I use most of the time.
Microsoft Word 2008 has a new feature called citations, basically a simple reference manager. This feature first appeared in Office 2007 for Windows. Citations integrates nicely with your Word document, but can't handle the more sophisticated needs of a research paper, e.g. automatic importing form online databases and dozens of reference styles for all the journals you possibly want to submit to.
Unfortunately you can't use the current version of Endnote with Microsoft Word 2008. Thomson Scientific (the Endnote publisher) is working on a version for Microsoft Word 2008. The update is made more difficult by the fact that support for Visual Basic for Applications (VBA) was dropped in Office 2008. The alternative reference managers Bookends and Sente also currently don't work with Microsoft Word 2008.
Microsoft Word 2008 by default uses the new XML-based .docx format introduced in Office 2007 for Windows. This format was originally not supported by Nature, Science and other STM publishers (read this Nascent post for the reasons behind it). Nature is now able to accept Word 2007 (and Word 2008) files, but this might not necessarily be true for other publishers.