RootsMagic president Bruce Buzbee calls version 4 the biggest release in our 20-year history of making genealogy software.
New features include integrated web searching, improved source citation, sharing events among multiple persons, creating pre-defined groups of persons, person and place mapping, recording DNA tests and improved navigation and data entry.
RootsMagic 4 includes RootsMagic To-Go, which lets you install the program onto a USB drive, transfer data between it and your computer, and take your data with you anywhere. (Look for our article on running genealogy software from a flash drive in the May 2009 Family Tree Magazine.)
The program can directly import data from Personal Ancestral File, Family Tree Maker (through version 2006), Family Origins and Legacy Family Tree. Its certified to work with New FamilySearch, FamilySearchs Web-based program thats being rolled out to LDS churches and will eventually be publicly available.
Addition: I asked Buzbee what happens when your RootsMagic 4 beta version expires. After March 31, the beta version reverts to a trial version, which has some disabled features and limits the amount of information you can enter. If you want to save what you entered in the beta version, you should export a GEDCOM before March 31.