Here is a link to the space weather website's account of the latest solar flare. By all accounts, this will be one of the biggest flares EVER - the last time one this big was seen, they had to extend the scale to accomodate it, and this one is thought to be bigger still. This one should only result in minor effects on earth, but if it had been aimed right at us, like the last few were, we could see some rather extreme effects, rolling blackouts, satellite failures, etc. Space Weather for more details.