If you are using ver 2.7 now, you can automatically upgrade to 2.7.1 via the Tools->Upgrade menu, or you can download the package and upgrade manually.
If you’re using WordPress version that is below 2.7, you will need to manually download and upgrade to this new version.
2.7.1 fixes 68 tickets. The update includes 6 tickets with a high rating and more than 50 rated as normal. The update fixes security holes and will not alter the database and should not break anything including plugins or themes.
All my themes are working well on WordPress 2.7.1.
