Wifi mostly solved

For my purposes, it's solved. But if you use WEP or no wifi security, there would need to be changes.

I posted this at mini-modding, but I'm replicating it here as well:

In the /tmp/hddmedia/wpa.conf file I have the following (replaced 'thessid' with the SSID used, and 'thepassphrase' with the passphrase used:
wpa.conf

ctrl_interface=/tmp/net/wpa_supplicant
ctrl_interface_group=root

network={
ssid="myssid"
proto=WPA RSN
key_mgmt=WPA-PSK
pairwise=TKIP CCMP
group=TKIP CCMP
psk="thepassphrase"
}

since the interface is at /tmp/net I have to create the directory. And since the file is stored on the 4th partition, I also needed to mount that. Also, I wanted to make sure the wired LAN was also recognized if present. So here's what is at the beginning of my /usr/local/etc/rcS file:
/usr/local/etc/rcS

mount /dev/ide/host0/bus0/target0/lun0/part4 /usr/local/etc/dvdplayer/hdd/volumes/HDD1
ln -s /usr/local/etc/dvdplayer/hdd/volumes/HDD1 /tmp/hddmedia
mkdir /tmp/net

echo 'nameserver 127.0.0.1' > /etc/resolv.conf
udhcpc -p /var/lock/udhcpc_eth0.pid -t 15 -b -s /etc/udhcpc.script -i eth0

modprobe ehci-hcd
modprobe ohci-hcd
sleep 2
ifconfig wlan0 up
iwconfig wlan0 essid "myssid"
wpa_supplicant -P/var/lock/wpa_supplicant.pid -D ipw -c /tmp/hddmedia/wpa.conf -i wlan0 -B
udhcpc -p /var/lock/udhcpc_wlan0.pid -t 15 -b -s /etc/udhcpc.script -i wlan0

The second udhcpc takes about 30 seconds to run, and then it still doesn't start responding to pings until after another minute has passed.

Now I'm sure there's going to be a better way to do what I've listed above. Like do we really need to have udhcpc staying as a running process after it has assigned the IP address? I don't know. But this is a starting point that works at least.

There is a script already on the ScreenPlay in the /etc directory called udhcpc.script. It's already there, but for reference here is the listing:
/etc/udhcpc.script

#!/bin/sh
# udhcpc script edited by Jason Lee

[ -z "$1" ] && echo "Error: should be called from udhcpc" && exit 1
RESOLV_CONF="/etc/resolv.conf"
DHCP_OK="/var/lock/dhcp.ok"
DHCP_OK2="/var/lock/dhcp."
[ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"
[ -n "$subnet" ] && NETMASK="netmask $subnet"

case "$1" in
deconfig)
/sbin/ifconfig $interface 0.0.0.0
;;

renew|bound)
/sbin/ifconfig $interface $ip $BROADCAST $NETMASK

if [ -n "$router" ] ; then
echo "deleting routers"
while route del default gw 0.0.0.0 dev $interface ; do
:
done

for i in $router ; do
route add default gw $i dev $interface
done
fi

echo -n > $RESOLV_CONF
# [ -n "$domain" ] && echo search $domain >> $RESOLV_CONF
[ -n "$domain" ] && echo domain $domain >> $RESOLV_CONF
for i in $dns ; do
echo adding dns $i
echo nameserver $i >> $RESOLV_CONF
done
echo ok > $DHCP_OK
echo ok > $DHCP_OK2$interface
;;
esac

exit 0