Hi, How secure is an encrypted wallet?
It depends on which software/web site you are using (bitcoin qt, blockchain.info etc), the length of the password, the randomness of the password, whether the encrypted wallet is available to others (e.g. is it ONLY on your computer or is it on a public web server), does your computer have malware and other factors. If you used "password" as the password and posted the wallet on a public server, it would not be secure. If you used a good password, only had the wallet on a non-internet-connected computer, it would be much safer.
If it has been compromised (e.g. off your computer somewhere with an easy to guess password), you should create a new address and send everything to that in order to prevent someone from stealing your bitcoins. (And make sure you don't have malware).