While there was no official release, it appears that the second version of Redhat’s free “Liberation” fonts are available as an attachment on this bug report. This new version has full hinting information, which should improve rendering at small sizes on low-DPI displays (read: your computer monitor).
Below’s the screenshot. Surely, an improvement over the non-hinted version, but I don’t think it beats Windows’ rendering of Arial or Segoe UI. (rendering settings are full BCI-enabled hinting + subpixel rendering on Ubuntu 7.10)