Solar flares are a scientific certainty.
Rain is also a certainty. But can weather forecasters with any reliability say in 2011 there will be major floods that will disrupt commerce, farming etc.? Of course not!
The Sun is far more complex that our earth weather. We know little of the solar cycle other than it exists. There is big debate if were are at the bottom of the cycle right now... or if it won't happen until the spring of 2007.
In 2000 we had a direct hit by an X5 solar flare (hugely bigness). I think that the GPS systems and everything else handled it just fine.
Cycle 24 looks like it will be strong but as far as I see it, no reason to serve fear burgers just yet.