While I appreciate the fact that there have been plugins produced to hack this into WordPress, this "feature" needs to be baked into the core.
Bloggers need to have the flexibility of capturing more user data than the currently extremely limited information available natively in WordPress.
On top of that, this data is among the most valuable and sensitive information in the database. For this reason it should not be left to plugins which always fall out of date or which could contain vulnerabilities.
Case in point: Userextra and Usermeta were built for WP 1.X and CUEF has comments from the author such as:
"...this version is UNSUPPORTED and OBSOLETE because the new plug-in uses WordPress >= 2.1.x
I have no time to support this legacy plug-in ..."
WordPress needs to incorporate this functionality into the core so that we can count on our data being safe and available in 5, 10 or more years - not just today.
John