Thanks, heper!. Your post helped me a lot. I had the same suspicion , but got scared from the new 2.2 advanced routing screen :-)
For anyone in the future who might have the same problem.
On Pfsense 2.2, go to NAT -> Outbound NAT.
Switch to Hybrid NAT.
Add entry on WAN(most likely) for NAT. Source should be your Openvpn LAN of the remote site. Please have in mind that in my case there was NO NAT(on purpose) between openvpn remote LAN and tunnel net. In case you have such NAT, you might need to change advanced NAT rule, source to be the tunnel net.