You have thought it might happen eventually and here we are. After long deliberation over at Slackware HQ have decided that support for the 32 bit architecture will be dropped as 64 bit is "the future". As another reason it was stated that this also brings the distribution in line with other major Linux distributions and vendors which is important to the developers as they don't like falling out of line with the wider Linux ecoverse.
The 'Current' development branch in Slackware hasn't moved for a while. Almost a year after the last stable Slackware the repositories are still on KDE 4.5.5 and Xfce 4.6.2, and here's why! The Benevolent dictator for life has finally had enough.
