I have just tried to upgrade my N70 using the Nokia Software Updater and encountered only one problem.
I've posted the solution here in the hope it will help others who may come across the same problem.
If you go through the process of upgrading and it fails, and when you try to power the phone up it doesn't work - don't fear - you (probably !) haven't ended up with a brick.
If you take the battery out and put it back in the phone should then start without a problem.
The reason why this happens is because you probably have PC Suite minimized in the System Tray next to your clock - if you quit that and re-run the upgrade process it will go through without any problems.
Hope this helps.
Regards,
Edward
Regards,
Edward