OK - so we had a bit of a false start before.... but...
Office Mobile 6.1 has now been released for Windows Mobile 5.0 Pocket PC and Windows Mobile 6 devices.
The upgrade is a FREE download from Microsoft.com and will allow you to open and edit Office 2007 file format documents from Word (.docx) and Excel (.xlsx) You can also view Powerpoint 2007 (pptx) documents.
Other improvements include:• Enhanced viewing experience for charts in Excel Mobile.• Ability to view SmartArt in PowerPoint Mobile.• Ability to view and extract files from compressed (.zip) folders.
This free upgrade works only for Windows Mobile powered devices that have an earlier version of Office Mobile. If your Windows Mobile powered device does not have Office Mobile applications, this upgrade will not work for you.
You can download it from HERE