NetworkManager runs into this since it uses /sbin/ip to do routing table stuff
and a few other things...  The result is that NM is unable to add any entries to
the routing table.  I've yet to figure out what the actual problem here is.

I've tested some ip route options and it seems to work. When exactly it fails?
Did you manage to figure this out? I don't use NM here and also I haven't found
any problem with iproute so far. 

I don't know at which point it fails; however, I reinstalled rawhide
iproute-2.6.14-1 and stopped networkmanager and dispatcher, removed them from
startup, rebooted, and now the routing table is populated and resolv.conf is
correct and the network is reachable.  So, seems there is some relationship
between networkmanger andf iproute that may be broken.

I now see lots of these messages in /var/log/messages:

Sep 15 06:48:58 localhost NetworkManager: nm_ip4_config_get_broadcast: assertion
`config != NULL' failed
Sep 15 06:48:58 localhost NetworkManager: nm_ip4_config_get_netmask: assertion
`config != NULL' failed

Installed today's updates from rawhide (including iproute-2.6.14-1) and I
noticed the following behavior:

On boot (with networkManager) interface is up (i.e., has address from DHCP, but
no  routes).

If I select the NetowrkManager icon and reselect 'wired network', it now
correctly brings up the interface including routes. 

NetworkManager only sees my wired interface; doesn't see my wireless one.
'iwconfig eth1' says 'no such device', etc.

Following messages from /var/log/audit/audit.log:

type=AVC msg=audit(1126794443.402:21): avc:  denied  { read } for  pid=2972
comm="killall" name="mls" dev=selinuxfs ino=12
scontext=system_u:system_r:NetworkManager_t:s0
tcontext=system_u:object_r:security_t:s0 tclass=file
type=SYSCALL msg=audit(1126794443.402:21): arch=40000003 syscall=5 success=no
exit=-13 a0=bfeac3b4 a1=8000 a2=0 a3=8000 items=1 pid=2972 auid=4294967295 uid=0
gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 comm="killall"
exe="/usr/bin/killall"
type=CWD msg=audit(1126794443.402:21):  cwd="/"
type=PATH msg=audit(1126794443.402:21): item=0 name="/selinux/mls" flags=101 
inode=12 dev=00:0d mode=0100444 ouid=0 ogid=0 rdev=00:00
type=AVC msg=audit(1126794446.278:22): avc:  denied  { read } for  pid=2991
comm="killall" name="mls" dev=selinuxfs ino=12
scontext=system_u:system_r:NetworkManager_t:s0
tcontext=system_u:object_r:security_t:s0 tclass=file
type=SYSCALL msg=audit(1126794446.278:22): arch=40000003 syscall=5 success=no
exit=-13 a0=bfafa6b4 a1=8000 a2=0 a3=8000 items=1 pid=2991 auid=4294967295 uid=0
gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 comm="killall"
exe="/usr/bin/killall"
type=CWD msg=audit(1126794446.278:22):  cwd="/"
type=PATH msg=audit(1126794446.278:22): item=0 name="/selinux/mls" flags=101 
inode=12 dev=00:0d mode=0100444 ouid=0 ogid=0 rdev=00:00

Not sure if this is related.....

OK, I think I've tracked this down.....

NetworkManager is trying to execute 'ip' commands with an argument of 'address'.
This appears no longer to be accepted ('addr' is accepted).

Looks like either NetworkManager needs to change to use 'addr', or ip needs to
change to accept 'address'.

Below is a list of the /sbin/ip commands executed by selecting the
NetworkManager icon along with any output.

route flush dev eth0
address flush dev eth0
Object "address" is unknown, try "ip help".
route del default
RTNETLINK answers: No such process
address flush dev eth0
Object "address" is unknown, try "ip help".
route flush dev eth0
Nothing to flush.
neigh flush all
-6 address add fe80::208:dff:fe89:dbdc/64 dev eth0
Object "address" is unknown, try "ip help".

Scripting /sbin/ip to change 'address' to 'addr' makes it work.

Ok, fixed in CVS and we'll try to put out an NM update very very soon.  Thanks
for the help!

Believe this is closed in RAWHIDE, no?

Yes.