WPA is good only if you use a good password. Someone can still guess your password or use a dictionary attack using common words to try and get into your network. For example, the password "goawayhackers" could be guessed eventually but a longer and more random password would not be easily broken.
Go to http://www.grc.com/passwords to get a random password. Save it in a file somewhere or write it down and that's as secure as you can get today with wireless without using VPN.