> 1. You don't want it to be serving media.
>
> 2. If you really want USB see #1.
>

Meh.  I think most of these guys are used to securing datacenters,
where having dedicated machines for each purpose is standard security
practice.

If your just setting up your home network, and the media you are
serving it the typical stuff like mp3s, etc, I wouldn't have any
concern at all about serving media from the same box that you are
using as your firewall.  It's certainly not worth the electric bill to
run to PCs 24x7 when one will do just fine.

If they can compromise your firewall, I can't see how it matters if
the media is being served by the firewall, or by a machine behind the
firewall - they could reach the media either way.

However, many of these dedicated boxes do look fun, and they don't use
as much power as a second full system.  Personally, I use a Linksys
WRT54GL - http://www.newegg.com/Product/Product.aspx?Item=N82E16833124190
- and I run tomato - http://www.polarcloud.com/tomato - on it.  It's
awesome.

Tomato also supports many other wireless routers - some of which have
USB connections that you can attach storage to - and serve the media
directly from the wireless router.