I have used this method on the micro hero 1.3, CyanogenMod v188.8.131.52 and I am just about to set it up on micro hero 1.4.
I have read on another site that this line should be added to the very end to change it back to read only
"mount -o ro,remount -t yaffs2 /dev/block/mtdblock3 /system"
The wifi modem at my G/Fs mothers has no internal PPPoE login and her adsl connection needs a PPPoE login, Android cant do this or I havnt been able to find and app that does.
I use my laptop(with 2 wifi cards, one internal and 1 external(pcmcia)) to do the PPPoE login(internal wifi) on the laptop and then share this connection via ad-hoc(external wifi) to my G1.
One thing that I would like to point out, if I lose the connection between the G1 and the laptop, I have to reboot the laptop to get it to share the internet again.I haven't worked out why yet.
I have ordered a new modem/wifi/router of ebay that will do away with all this crap, but for now it is a work around that does works, until the new modem arrives.