After 2 months released of WordPress 2.7, 2.7.1 is the first version of 2.7 maintenance release and is now made available to you for download. The 2.7.1 version fixes 68 tickets. Upgrade can be easily performed from 2.7 to 2.7.1 via the Tools -> Upgrade menu. You can also choose to download the WordPress 2.7.1 package and upgrade it manually.
However, you can read the full changeset between 2.7 and 2.7.1 to understand fixes on the previous version. So, do upgrade your WordPress to WordPress 2.7.1 and hopefully I will be upgrading it by this weekend or next week.