Google brought up this link showing the IP details for supl.nokia.com:
http://supl.nokia.com.ipaddress.com/

If I add 35.157.6.107 supl.nokia.com to /etc/hosts on my N900, it seems to work (nokia maps works and finds accurate location, location-test gets fast connection to satellite etc)
So until/unless the SUPL server running on the Amazon AWS instance answering at that IP address goes away, this should be a good short term fix.

That IP address is probably the best one to use since its the actual last known IP address of supl.nokia.com.

Going forward, maemo should run its own SUPL server as recently suggested by DocScrutinizer05 and freemangordon...

EDIT:
I found this other link
http://www.ip-tracker.org/locator/ip...Supl.nokia.com
which lists an IP address of 52.22.201.16 (also an AWS instance)
along with https://www.robtex.com/dns-lookup/supl.nokia.com that lists a bunch of IP addresses.

The first one I found seems to work though so I will stick with it until something else happens (supl.nokia.com DNS returns a valid IP again, alternative SUPL server is set up or whatever)

EDIT 2:
Its possible the different IP addresses all point to different instances running the same SUPL code (i.e. distributing the load over multiple Amazon AWS instances) or something (I dont know how Amazon AWS works)