Of course, of course! Eliminating lead contamination from gasoline only works with eliminating it from gasoline itself. But with solder different ways are possible to prevent lead from contaminating our environment. Just to prohibit it isn't a good idea, unless lead free solder can be handled reliably.

Besides the bad effects Steve already stated (e.g. whiskering), I will only mention one problematic issue here:
"Normally, thermal expansion rates for epoxy encapsulant and metal leadframe materials are linear and remain fairly close at temperatures approching 160°C. At lower temperatures the difference in expansion rate of the two materials is not great enough to cause interface separation. However, when the package reaches the glass-transition temperature of epoxy (typically 160-165°C), the thermal expansion rate of the encapsulant increases sharply, and the material undergoes a transition into a plastic state. The epoxy begins to expand at a rate three times or more greater than the metal leadframe, causing a separation at interface.
When this happens process residues and even solder can enter the cavity created by the separation and become entrapped when the material cools. These contaminants can eventually diffuse into the interior of the package, especially in the presence of moisture. The result is die contamination, excessive leakage, and even catastrophic failure. Unfortunately, electrical tests performed immediately following soldering process may not detect potential flaws."
So far, from an application note from National Semiconductors.

It's a well proven matter of fact, that failure rate increases with the time period (and over-temperature!) SMD-packages are exposed to temperatures higher than glass-transition temperature. As long as epoxy encapsulation material cannot be trimmed to show higher glass-transition temperature, which is the situation right now as far as I know, using lead free solder with its drastically higher melting point presents a big problem!

Kai