Being a DBA is more than just knowing about SQL: it's about the technology which SQL runs on, which includes servers and storage. I'm naturally interested in hardware, so I enjoy keeping up-to-date. Becoming acquainted and staying current with new technologies will not take up too much time, plus it will make you a better DBA. Below is a few resources that I have used to keep up-to-date with hardware and storage.

Web Sites and Blogs

AnandTech

AnandTech Enterprise

CPU World

CPU-Z

Crystal Mark IO Tools

Free SQL Server Hardware Book from Red Gate

GlennBerry: SQL Server Hardware Tidbit A Day

Intel ARK Database

Real World Technologies

Sql Server Performance Blog

SQL Skills Hardware Blog

Storage Review

The SSD Review

Tom’s Hardware

Transaction Processing Performance Council