http://ftalphaville.ft.com/blog/2007/07/30/6213/cds-report-its-a-very-brave-man-or-woman-who-calls-the-end-to-this/?source=rss

and one person thinks it may go to 1000bps

http://www.bloomberg.com/apps/news?pid=20601087&sid=a4CHnE.bPy6s&refer=home

I would be very surprised to see it go to this level - the underlying single names are currently trading around 400bps so assuming sufficient liquidity it would be possible to sell index protection and buy the underlying - however, liquidity in single name is nowhere near as high as in indices.