We are currently working to support the new Office Open XML file formats, such as XLSX and PPTX, which were introduced in Office 2007.
Development for this is in a svn branch, but we are please to announce our first preview release containing this support. Users interested in the OOXML support should download the - POI 3.5 beta 5 + POI 3.5 beta 6 the source and binaries from their local mirror. People interested should also follow the dev list to track progress.
The release is also available from the central Maven repository - under Group ID "org.apache.poi" and Version "3.5-beta5". + under Group ID "org.apache.poi" and Version "3.5-beta6".