With this morning's sources (and I see no updates in
sys/arch/i386/conf since then):

all ===> etc/i386/floppies/bootfloppy
#    create  bootfloppy/netbsd (from: /usr/obj/auto-current/i386/distrib/i386/floppies/instkernel/netbsd-INSTALL.gz)
#    create  bootfloppy/boot1.fs (from: boot  netbsd)
PAX=/usr/obj/auto-current/tools/bin/nbpax sh /n0/gdt/NetBSD-current/src/distrib/common/buildfloppies.sh  -i "/usr/obj/auto-current/tools/bin/nbinstallboot  -mi386 @IMAGE@ /usr/obj/auto-current/destdir/i386/usr/mdec/bootxx_ustarfs" -p  -m 2 -s .fs  boot 2880 boot  netbsd
Running instboot: /usr/obj/auto-current/tools/bin/nbinstallboot -mi386 floppy.9470.tar /usr/obj/auto-current/destdir/i386/usr/mdec/bootxx_ustarfs
buildfloppies.sh: Image is 6144 bytes (6 KB) too big to fit on 2 disks

*** Failed target:  boot1.fs
*** Failed command: PAX=/usr/obj/auto-current/tools/bin/nbpax sh /n0/gdt/NetBSD-current/src/distrib/common/buildfloppies.sh -i "/usr/obj/auto-current/tools/bin/nbinstallboot -mi386 @IMAGE@ /usr/obj/auto-current/destdir/i386/usr/mdec/bootxx_ustarfs" -p -m 2 -s .fs boot 2880 boot netbsd
*** Error code 1

Stop.
nbmake: stopped in /n0/gdt/NetBSD-current/src/distrib/i386/floppies/bootfloppy