While reading http://thread.gmane.org/gmane.linux.network.networkmanager.devel/12056/focus=12210 I've got a feeling that NetworkManager should be able to create a sensible order of nameservers in /etc/resolv.conf. If the order of nameservers should be (I have checked that VPN routes should be used only for VPN traffic):

VPN (if VPN all traffic is routed over the VPN)
Primary connection
Others 

# after using NM-vpnc
jakoubek:~$ cat /etc/resolv.conf
# Generated by NetworkManager
domain redhat.com
search redhat.com Kaprova ceplovi.cz
nameserver 10.32.63.5
nameserver 10.33.63.7
nameserver 192.168.1.1

# after using NM-openswan
jakoubek:~$ cat /etc/resolv.conf
# Generated by NetworkManager
domain redhat.com
search redhat.com Kaprova ceplovi.cz
nameserver 10.32.63.5
nameserver 10.33.63.7
nameserver 192.168.1.1
jakoubek:~$ ip route 
209.132.186.250 via 192.168.1.1 dev eth0  proto static 
192.168.122.0/24 dev virbr0  proto kernel  scope link  src 192.168.122.1 
192.168.0.0/17 dev eth0  proto kernel  scope link  src 192.168.1.3  metric 1 
10.36.0.0/16 dev eth0  proto kernel  scope link  src 10.36.8.203 
172.16.0.0/16 dev eth0  scope link  src 10.36.8.203 
10.0.0.0/8 dev eth0  scope link  src 10.36.8.203 
default via 192.168.1.1 dev eth0  proto static 
jakoubek:~$ 

jakoubek:~$ rpm -qa NetworkManager\*
NetworkManager-openswan-0.8.0-5.20100411git.fc14.x86_64
NetworkManager-gnome-0.8.1-6.git20100831.fc14.x86_64
NetworkManager-debuginfo-0.8.1-6.git20100831.fc14.x86_64
NetworkManager-vpnc-0.8.1-1.fc14.x86_64
NetworkManager-0.8.1-6.git20100831.fc14.x86_64
NetworkManager-glib-0.8.1-6.git20100831.fc14.x86_64

Expected result:
NetworkManager should recognize that 192.168.1.1 is the local DNS server and generate this resolv.conf:
jakoubek:~$ cat /etc/resolv.conf
nameserver 192.168.1.1
nameserver 10.32.63.5
nameserver 10.33.63.7