In the world of office suites there isn't much room for anybody other than Microsoft, but their high prices have long been a setback for many. This is particularly true for Macs, where Office has a considerably smaller market share than in Windows, but that was all the opening Sun needed to port StarOffice 9 to the Mac at the cost of $35 for an individual license and $25 for a business user.
The native Mac support should prove to be a decent selling point, along with the ability to open the standard Open Document formats and the Microsoft-backed Open XML format that Office 2007 uses. StarOffice does face stiff competition, including from the very software it is based upon, OpenOffice.
They might be able to make headroom here, however, as Microsoft has taken a lot of flak for Office on the Mac, due to lack of support for many important features, slower updates than the PC and other factors.