They have been accepting Bitcoin for a long time before this. I have had banners been made for advertizing through them and I paid in Bitcoin.
I got 3 banners for $5 and the person doing it was happy to make adjustments without charging me.
The partnership will open up a whole lot more traffic and business to the site and it will allow for easy conversion for people who wants fiat.
I am still not a big fan of BTC to Fiat conversion, but I can see the need for some people to do it. {Bills have to be paid in fiat}