I'm a LastPass user and last night I was forced to change my master password. Initially I was a bit suspicious about the request, so I took all the measures to make sure it was a genuine request from LastPass.com. When I was sure it was a safe request, I changed my master password to something even stronger than it was.
I'm a paying user for their premium services, and in my opinion I must admit that their reaction to that casualty and possible data breach has been very open and reasonable. I would be very angry if instead they had an attitude like PSN. At least they took proactive countermeasures and are being honest to their customers, that attitude really deserves some kudos.