As long as "downloading list of changes" is running in the new update dialog, you cannot start downloading packages. Sometimes this can take quite a long time and I guess many people are not even going to read the changelogs. So, it would be good if you could press "install" even with the list of changes not fully downloaded.
Can't you just click cancel and then click install?
Can I? Maybe I can... well, I have not tried but then again I have never associated the cancel with this action (I would have expected the whole upgrade process to be canceled)
Was this fixed in yesterdays snapshot? Thanks.
*** This bug has been marked as a duplicate of bug 499590 ***