More Variation support, more standard document support, more bug fixes and an upgrade
checker (to make sure you can apply SP2)

Should keep those sites happier for longer

Details from http://blogs.technet.com/office_sustained_engineering/archive/2009/04/23/service-pack-2-for-the-2007-microsoft-office-system-available-today.aspx

Service Pack 2 for the 2007 Microsoft Office system available today!

We’re pleased to announce the release of all languages for Service Pack 2 for the
2007 Microsoft Office System, the 2007 Microsoft Office servers, and Windows SharePoint
Services 3.0. As promised, this post contains a list of the products that are patched
by SP2 with their corresponding knowledge base articles, information on how to obtain
the packages, and links to additional SP2 resources. We hope you’ll find this to be
one of the best service packs produced by the Office team ever!

How to obtain SP2

Recommended Method: Microsoft Update

We recommend using Microsoft Update to
apply SP2. Microsoft Update’s detection will determine the products and languages
you have installed and update your machine all at once.

Optional Method: The Download Center

If you choose not to use Microsoft Update, the SP2 packages are available for download
from the Microsoft Download Center. Please click here to
find links to the downloads.