Trolltech yesterday announced that it had released a second update of Qt and Qtopia 4.2. The substantial list of bug fixes can be found here; downloads for all platforms available here and GPL releases of Qtopia can be downloaded here. OpenSUSE have already released binaries which can be found at the usual downloads site.
Note that Trolltech has omitted to update the page for Mac downloads; you can, however, grab them from the mirrors here: Athens [http] [ftp], Chemnitz [http] [ftp], Iasi, Romania [http] [ftp], [rsync]. Each FTP site (Athens, [Chemnitz, Iasi) offers a 54Mb disk image with a binary of the Qt library, development tools and examples; it requires OS X Tiger to develop applications and 10.3.9 to run the tools (and, presumably, anything developed with the binary). I recommend not installing the examples (click the "Customise" button when it appears at the "Installation type" stage, and then de-select the examples package) because the installer hung when installing the examples on my machine.