The analysis in Bull market, B-wave and Beyond (2/18/11) warns that "one should be cognizant of the risk of a logical ending point ahead" based on wave structures and the arrival of the first Fibonacci time turning point.
The market has certainly delivered a swift drop this week (down 3.71% in SPX over three days), but also an equally impressive rebound from Thursday's low (up 2.04% in SPX to Friday's high). The broad market, as measured by Wilshire 5000, has now retraced a little more than 50% of its recent decline.
Therefore, the relevant questions for the near term are:
 Is the correction over and the next advance to a new high already in progress?
 Will there be follow-through to this week's decline to a lower low?
This week's low has now become a critical level.
On balance, risks to either the immediately bullish and bearish interpretation remain substantial. For bulls, the hope rally could have ended at the recent high (Chart 1, red count). For bears, the market may have started another multi-week/month advance since the recent decline may be large enough to be considered a correction at the minor or minute degree (Chart 1, green and blue counts).
However, risks are not overwhelmingly skewed in either direction. But here are some observations to consider.
 The 50-day MA has successfully supported the broader stock market and stocks rebounded sharply.
 There is no major lower lows (yet), implying that the uptrend remains intact.
 With the exception of INDU, other indexes closed above their 20-day MA Friday.
 Market internals (Chart 1) are respectable on the rebound Friday. The NYSE advance/decline issues ratio is comparable to the beginning of the next bull run following a prior pullback (light blue vertical lines) - with the exception of one instance in late November (light orange vertical line).
 If the market goes to a new high, the blue and green counts in Chart 2 offer the associated wave structure.
The blue count describes the decline as a zigzag, which works OK with cash indexes but not with futures.
The green count describes a complex correction (e.g. a running flat-like structure) that has actually started in mid-February (or even earlier), which works well with futures and INDU, but OK with the other cash indexes.
Note that the interpretation of the sell-off as the tail end of a larger sideways correction may not be too far fetched if one compares US with Russian RTSI (Chart 3) and UK FTSE (Chart 4), which have shared a high correlation with SPX for some time.
 Near term wave structure shows a respectable impulse wave decline, with the rebound potentially being an expanded flat or a zigzag (Chart 2, red count). A nine-wave decline is the clearest in Dow futures. If last Friday's high is indeed the start of the correction, the first impulse wave is never the end of the correction.
 Friday's rebound may be a successful retest of the underside of the upward trend line (Chart 1, blue dotted line), before the sell-off resumes early next week.
Chart 6 presents 2 immediately bullish counts (which addresses the minor overlaps) and 2 bearish counts on ES (SPX). One can map these onto YM (INDU) (Chart 7).