With the current release only VPN bonding can be used to increase the bandwidth and reliability of a link between two sites.
The 1.0.beta6 release will include the Net Balancer component that allows to balance the traffic on multiple WAN links.
Exactly how does the NetBalanver work? Would this mean that we no longer need the vpn links to bond the adsl lines?? If this is the case, I can see a potential issue…BT implemented source address filtering a few years ago which means that is you send a packet out on line 1 which has a source address of line 2 then the BT network will drop the packet.