My android phone was stolen. How worried should I be with all my google data inside the phone?

Ok, so my samsung galaxy 5 was stolen. I had gmail, calendar, twitter(tweetdeck), facebook, ... all my personal data in it. I didn't have any app installed that could wipe this information from a sms (tried to install PlanB through the market, but I don't think it'll work). I already changed my google password and I'm proceeding to change facebook and twitter as well. Is this enough? How much of this information (old emails, tweets, ...) are saved in the phone's memory? Can I prevent access to this just by changing my passwords? I've blocked my SIM card with my provider, so I guess the phone currently have no internet or telephone line access. Here in Brazil we can also block a stolen cell phone with the IMEI number, but I don't know exactly what this means. Will this brick the phone or just prevent it from being registered in the network?