Yeah, I think S&P eventually breaks below the channel. The ABC type of downtrend is fairly common, and many non-US markets have already started the C wave. It's not guaranteed, but the odds favour this.
I've been watching the relationship between the VIX index and the VXX (short term VIX futures ETN). Normally, VXX underperforms, but ever since the beginning of Aug when the markets initially plunged, it has been outperforming. So traders in VIX futures believe that volatility will be higher in the near future - a bit scary if you ask me. Unfortunately, VXX only started trading in 09, so I don't know how similar the Greece thing is to the Lehman/Tarp debacle.
I don't think we'll get a collapse like 08, but it cannot be completely counted out. I'm expecting a milder breakdown, but it could still be quite scary. But when it's over, there will be a nice opportunity on the long side.