We now have syntax highlighting for a host of languages through Google Prettify. Regrettably, the default set:
lang-bsh
lang-c
lang-cpp
lang-cs
lang-csh
lang-css
lang-hs
lang-html
lang-java
lang-js
lang-lisp
lang-lua
lang-ml
lang-perl
lang-php
lang-proto
lang-py
lang-rb
lang-scala
lang-sh
lang-sql
lang-vb
lang-xml
doesn't include VHDL, which (based on a comparison of the vhdl, verilog, and asm tags) is the second-most used language on our site (The first is c, of course...).
VHDL already has a plugin for Google Prettify. If this is enabled, we'll be better able to serve this portion of our community.