If you use a VPN, you should be protected from "local" man-in-the-middle (MITM) attacks. By "local", I mean between your computer and the VPN server. A VPN doesn't protect you from a MITM attack between the VPN server and the webserver you are connecting to. But it does protect you to the VPN server if you are at an Internet cafe, hotel, or other untrusted network.
At least that's true for most VPNs that use software based on OpenVPN, which uses OpenSSL for encryption. A copy
of an email from James Yonan was recently posted to the OpenVPN User's list. Bottom line of the email: OpenVPN uses OpenSSL for encryption, and OpenSSL has been patched since 2002 for the vulnerability which most people think is exploited by BEAST. As long as your VPN software uses a patched version of OpenSSL you should be covered, at least for the "local" MITM attack.
For example, VPNs based on Tunnelblick
, a free and open source GUI for OpenVPN on Mac OS X is not vulnerable.