I want to thank B2L and quantumrand for your accurate responses. I exchanged the N1 and I am now a happy owner of a Nexus S
Some tools that I found useful during this week of researching are:
Android System Info
https://market.android.com/details?id=com.electricsheep.asi&feature=search_result
which provides lots of detail about your phone. Regarding my interest here, the memory, for the NS it reports (after loading the apps that I had on the N1):
Data Max: 0.98GB/ Free 848MB
External Storage Max: 13.31GB/ Free: 12.13GB
Compared to the N1 that reported something like 196 MB Max and 26 MB Free
For the apps that you can move to SD, now it says something like move to USB storage, so those apps can still be moved out of the internal (1GB) memory, if I ever need it. So Thumbs up for the NS regarding memory!
Another tool that I want to share in this post is Disk Usage
https://market.android.com/details?id=com.google.android.diskusage&feature=search_result
which lists very nicely all apps and free space (that is visible with a non rooted device)