I am using a snapshot of netbsd-2.0beta from releng.netbsd.org (18 May), 
and for some reason, my usb mouse no longer works.
I think that this may be a problem with the usb hub, rather than the 
mouse, but I don't have another device to check this.
I used 1.6ZK for some time, and had had no problem, until I recently 
updated NetBSD

dmesg output: (with a ps2 mouse plugged in also)

NetBSD 2.0_BETA (GENERIC) #0: Tue May 18 10:46:27 UTC 2004
        
autobuild@tgm.netbsd.org:/autobuild/netbsd-2-0/i386/OBJ/autobuild/netbsd
-2-0/src/sys/arch/i386/compile/GENERIC
total memory = 511 MB
avail memory = 493 MB
BIOS32 rev. 0 found at 0xf9ee0
mainbus0 (root)
cpu0 at mainbus0: (uniprocessor)
cpu0: AMD Athlon XP 2000+ (686-class), 1674.51 MHz, id 0x662
cpu0: features c3c3fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
cpu0: features c3c3fbff<PGE,MCA,CMOV,PAT,PSE36,MMXX,MMX>
cpu0: features c3c3fbff<FXSR,SSE,3DNOW2,3DNOW>
cpu0: I-cache 64 KB 64b/line 2-way, D-cache 64 KB 64b/line 2-way
cpu0: L2 cache 256 KB 64b/line 16-way
cpu0: ITLB 16 4 KB entries fully associative, 8 4 MB entries fully 
associative
cpu0: DTLB 32 4 KB entries fully associative, 8 4 MB entries 4-way
cpu0: 8 page colors
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
pchb0 at pci0 dev 0 function 0
pchb0: VIA Technologies VT8377 Apollo KT400 CPU to PCI Bridge (rev. 0x80)
agp0 at pchb0: aperture at 0xe0000000, size 0xe500000
ppb0 at pci0 dev 1 function 0: VIA Technologies VT8377CE CPU-AGP Bridge 
(KT600)
(rev. 0x00)
pci1 at ppb0 bus 1
pci1: i/o space, memory space enabled
vga1 at pci1 dev 0 function 0: ATI Technologies product 0x4152 (rev. 0x00)
wsdisplay0 at vga1 kbdmux 1: console (80x25, vt100 emulation)
wsmux1: connecting to wsdisplay0
ATI Technologies product 0x4172 (miscellaneous display) at pci1 dev 0 
function 1
 not configured
rtk0 at pci0 dev 13 function 0: Realtek 8139 10/100BaseTX
rtk0: interrupting at irq 11
rtk0: Ethernet address 00:50:fc:27:72:cf
ukphy0 at rtk0 phy 7: Generic IEEE 802.3u media interface
ukphy0: OUI 0x000000, model 0x0000, rev. 0
ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
viaide0 at pci0 dev 15 function 0
viaide0: VIA Technologies VT8237 ATA133 controller
viaide0: bus-master DMA support present
viaide0: primary channel configured to compatibility mode
viaide0: primary channel interrupting at irq 14
atabus0 at viaide0 channel 0
viaide0: secondary channel configured to compatibility mode
viaide0: secondary channel interrupting at irq 15
atabus1 at viaide0 channel 1
uhci0 at pci0 dev 16 function 0: VIA Technologies VT83C572 USB 
Controller (rev.
0x81)
uhci0: interrupting at irq 5
usb0 at uhci0: USB revision 1.0
uhub0 at usb0
uhub0: VIA Technologies UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhci1 at pci0 dev 16 function 1: VIA Technologies VT83C572 USB 
Controller (rev.
0x81)
uhci1: interrupting at irq 5
usb1 at uhci1: USB revision 1.0
uhub1 at usb1
uhub1: VIA Technologies UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
uhci2 at pci0 dev 16 function 2: VIA Technologies VT83C572 USB 
Controller (rev.
0x81)
uhci2: interrupting at irq 11
usb2 at uhci2: USB revision 1.0
uhub2 at usb2
uhub2: VIA Technologies UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub2: 2 ports with 2 removable, self powered
VIA Technologies VT8237 EHCI USB Controller (USB serial bus, interface 
0x20, rev
ision 0x86) at pci0 dev 16 function 4 not configured
pcib0 at pci0 dev 17 function 0
pcib0: VIA Technologies VT8237 (Apollo KT600) PCI-ISA Bridge (rev. 0x00)
auvia0 at pci0 dev 17 function 5: VIA VT8235 AC'97 (rev 0x60)
auvia0: interrupting at irq 11
auvia0: ac97: Avance Logic unknown (0x414c4760) codec; no 3D stereo
auvia0: ac97: ext id 9c4<AC97_23,LDAC,SDAC,CDAC,SPDIF>
audio0 at auvia0: full duplex, independent
isa0 at pcib0
lpt0 at isa0 port 0x378-0x37b irq 7
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
pckbc0 at isa0 port 0x60-0x64
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pms0 at pckbc0 (aux slot)
pckbc0: using irq 12 for aux slot
wsmouse0 at pms0 mux 0
pcppi0 at isa0 port 0x61
midi0 at pcppi0: PC speaker
sysbeep0 at pcppi0
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
npx0 at isa0 port 0xf0-0xff: using exception 16
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
isapnp0: no ISA Plug 'n Play devices found
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
Kernelized RAIDframe activated
wd0 at atabus0 drive 0: <ST380023A>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 76319 MB, 155061 cyl, 16 head, 63 sec, 512 bytes/sect x 156301488 
sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd0(viaide0:0:0): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using 
DMA data
 transfers)
atapibus0 at atabus1: 2 targets
cd0 at atapibus0 drive 0: <AOPEN   CD-RW CRW4852     1.00 20030123, , 
1.00> cdro
m removable
cd0: 32-bit data port
cd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2 (Ultra/33)
cd1 at atapibus0 drive 1: <MATSHITA CR-584, , QS14> cdrom removable
cd1: 32-bit data port
cd1: drive supports PIO mode 3, DMA mode 1
cd0(viaide0:1:0): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using 
DMA data
transfers)
cd1(viaide0:1:1): using PIO mode 3, DMA mode 1 (using DMA data transfers)
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs
wsdisplay0: screen 1 added (80x25, vt100 emulation)
wsdisplay0: screen 2 added (80x25, vt100 emulation)
wsdisplay0: screen 3 added (80x25, vt100 emulation)
wsdisplay0: screen 4 added (80x25, vt100 emulation)