I'm delighted to hear that someone is working on a replacement for libtool.  However, the only code in Autoconf itself that has anything to do with libtool is the code in 'autoreconf' that runs 'libtoolize'.  Before we can change that code to try using slibtool instead, slibtool would have to provide an equivalent ('slibtoolize'?), and the much more extensive code in Automake that integrates with libtool would also need to be updated so that it works correctly with slibtool as well.

Please discuss this with the Automake and slibtool projects, work out a plan for making all of that happen, and then report back here.  I'll leave this bug open but I'm marking it as blocked on work in other projects.