New in this release: Improved screen appearance, improved file locking, overlining, grammar checking (they did this for me? :), better localization as well as numerous additions to the suite's programs including Writer, Calc, Chart, Impress, Base.
The OpenOffice initiative has been funded for the most part by Sun Microsystems and there had been some concern from the community that the company's recent acquisition by Oracle might affect the project funding.
It appears that, at least for now, so far so good.
Note: If you don't have Java running on your system, OpenOffice will install the latest Java machine for your operating system.
The location / language-specific versions of OpenOffice 3.1 that are currently available (Windows, Linux and others) can be found at the project's download page here.