Well, during my upgrade to Feisty I installed the NVidia drivers' packages and they were updated. And since for some reason Ubuntu's NVidia drivers still don't work, I lost my X! So, once again, it's back to w3m to download and install the NVidia drivers from NVidia's website...
This is easy to solve, but I would rather that it didn't happen again. So I removed the Ubuntu packages from my installation.
sudo apt-get remove nvidia-glx
sudo apt-get remove nvidia-kernel-common
After doing this you must reinstall the NVidia drivers, because removing these packages also deletes a bunch of required files. As a bonus, you win about 100Mb of free space. :-)