The chart below says it all. There has been at least 5 major rallies in the Nikkei since 1989 (depending how you count), only to have the market tank even lower lows. Some of those rallies even lasted for a good period of time. The rally in the 2000s lasted over 5 years (rising some 140% from the 2003 bottom) , before new 20 year lows were reached in 2008.
If the US in entering a lengthy period of credit deflation (which is a theory I subscribe to), then there is a good chance the rally of 2009 will fail, and the markets will reach new lows. Unfortunately, I don’t think we will have the luxury of years before this rally peters out.
If anything meteoric rallies are sure-fire sell signals. Swift rallies (that cover a lot of ground in a short period of time) almost always occur during bear markets. The great rally of 2009 isn't any different.