Apparently (at least) 2 of the servers responsible for serving the static images and the JavaScript are down or otherwise unreachable. Affected are linux.unix.com and ubuntu.unix.com , while solaris.unix.com is still up. A check on this website confirmed it. Checked as of 2010-06-16 08:11 UTC.
Images not showing up as of "09:37:47 Wednesday, June 16, 2010 (UTC)"
Thanks!
Its a CDN issue (SimpleCDN) problem.
I've just moved all off the CDN and back on the main server for now. Should be OK within a hour (based on DNS TTLs).
Amazingly enough, the problem turns out to be this:
SimpleCDN simply deleted our account, without notice, warning, email, nothing....
(see attached)
Nice people! Not.
It was quite a bizarre experience!
I found it interesting when they deleted our account after we complained about it not being fixed, 10 months after we first reported it!
Now that's really interesting customer service !!
Sounds like a workable "Thou shalt not criticize thy hoster" attitude 
In all fairness, "you get what you pay for".... and SimpleCDN was very low priced and they also gave us some "free bandwidth credit" to help compensate for being unable to meet their stated QoS.
However, after frequent outages, Europe and Asian traffic served from the US for 10 months, and then deleting our account after complaining, I can't recommend them, LOL
Just being nosy here, but: how much traffic and disk space are we talking about here?
Very little disk space because of only small images and javascripts.
I can't tell you the exact monthly bandwidth used because they deleted the account with all the stats without giving any notice 
It is quite small, relatively speaking. The last email I sent to their sales guy said this:
I can't access the SimpleCDN web site (maybe they blocked my IP, LOL), but if you look at their web site and get the B/W limit for the lowest priced Hotcache service, which was $150 USD per month, we were using roughly 1 percent of that B/W ceiling.
When our "Mirror Bucket" service did not work as sold to us, they wanted us to shift to the $150 per month "Hotcache" service, but we only used 1 percent of the B/W ceiling of that service, which did not make sense. So when our "Hotcache" trail period was over, I wanted to switch us back to the agreed upon "Mirror Bucket" service, asking the question:
That was the second to last email I sent to them before my final complaint that seemingly resulted in our unannounced account deletion and subsequent forum outage.
---------- Post updated at 06:37 ---------- Previous update was at 06:26 ----------
Update:
Yes, SimpleCDN has blocked my IP address, LOL. I can get to their site if I use a proxy server.
I guess they did not like my blog post.
Also, I note that they do not list the $150 a month "Hotcache" service, only a $500 service, so I guess that was their "bait-and-switch" strategy as I thought. They offer a cheap service like their "Mirror Bucket" service (the "bait"), and then hope to sell you a more expensive service (the "switch").
Funny they blocked my IP, LOL.
I think I know why SimpleCDN blocked my IP address. They read my blog post and did not want me to have access to our trouble ticket log.
Kind of anticipating something like this from them, I saved all the relevant discussions in PDF, including the index of all the trouble tickets, which you might find interesting.
(attached)
Yes, using a proxy service I can access SimpleCDN, but they have blocked my primary IP address.
I mentioned to them in a trouble ticket that I was planning a "final report" blog article about our experience with SimpleCDN. That must have triggered our account deletion, immediate outage, and then subsequently our blocking IP address.
That is really great customer service! LOL.
Another added benefit from dropping SimpleCDN... overall performance has improved.