Hi I'm from CodeCogs. This last week has been somewhat interesting, it hasn't been a slashdot effect, more a Dos attack effect. But you're right, CC has been slower than it should be - and this is being rectified fast.
As for it being pulled. Not anytime soon. It will always be a free survice, so long as its in use. Made increasingly likely now two large companies are considering handing over control of their servers for us to support directly in exchange for public access. First steps to a truely worldwise distributed equation rendering network.
Also, previous services that I have used similar to this have been pulled or put behind a paywall, so I'm reluctant to use a web service like this.