I don't agree...
Did you run "Check Installation Medium" from the menu on the first boot screen?
If I boot my 11.2 DVD without an internet connection, it proceeds with the installation process.
I think that openSUSE 11.2 should install and, at the point that YAST would connect to the openSUSE repositories for updated packages and dependencies needed for the software to be installed, it would tell you there is no connection, that it is limited to the DVD, and that the installation will continue with what is on the DVD.
This is what I remember happening in previous versions of openSUSE. More posts will give more information, but I think your problem is something else.
Exactly when did you receive the error notice and what did it say?
This might be useful.