Along with the new name - Qt Extended, we have a completely, well almost completely, new build system. We have gotten rid of qtopiamake, and came up with qbuild! Qbuild, according to the 4.4.1 release documentation is "The QBuild tool replaces qmake, allowing more efficient processing of the build instructions contained in .pro files and better management of dependencies." http://doc.trolltech.com/qtextended4.4/release-4-4-1.html
For 3rd party developers, this means you will have to "port" your projects .pro files to qbuild. Qbuild looks for qbuild.pro files, so a simple rename will get you started. In real world experience, this also means you need to edit the .pro file a bit for qbuild.
If you have written any project for Qtopia 4, you might be familiar with this statement: qtopia_project(qtopia app) With qbuild, this is no longer needed, so if you have this in your .pro file, delete it.
This CONFIG+=qtopia_main becomes this CONFIG+=qtopia. For qbuild, you will also need to specify a TEMPLATE like this TEMPLATE=app TEMPLATE can be one of app, lib, plugin, or subdirs.
If you have any depends(libraries/foobar), you need to adjust it like this: MODULES+=foobar
Plugins need to add some more stuff PLUGIN_FOR=qtopia PLUGIN_TYPE=mediaengines
There is more information on qbuild Here and more on porting project files to qbuild Here
Qbuild also replaces make. So, to build your project, instead of make, you now need to type qbuild (assuming qbuild is in your PATH). If you have the correct INSTALLS in your project file, you can build packages by doing qbuild packages FORMAT=deb will create a nice debian style package for you. It will also build ipk and naturally, qpk's.