Notice that price has been carving out a long and painful ending diagonal formation. These are so annoying because prices stay at depressed levels for an extended period of time and trend slightly downwards, providing no relief. An ending diagonal is composed of 5 waves, 4 of which have completed thus far. A 5th wave drop that undercuts today's low (and possibly the 10/10/08 low) would complete the pattern and lead to an explosive, unrelenting rally to 1050 and higher. Today's rally washed out the bears. One final decline would washout the remaining bulls, and undercutting the 10/10/08 low would respark the "crash" fears.
However, there is also some good evidence for this rally sticking. Notice that there have been 3 high accumulation days (higher volume up days) and only 2 distribution days since 10/10. This is pretty constructive. Also, see the following chart:
This 1h chart of SPX shows that the rally from 839.80 could be counted in 5-waves, and the decline is clearly in 3-waves. Also, price is breaking above the downtrend line. Thus, if the market gaps up, it would likely confirm that the bear market is done for now. A good re-entry point would be the topside of that trendline.
In summary, I favor the possibility of one last washout decline to complete the elliot wave pattern. However, a gap up would reduce the possibility of this scenario.