I recently upgraded from 1.4.2 to 1.5.1 on my Quadra 650, and have 
encountered a few issues with the release (1.4.2 worked flawlessly 
for me).  First, 1.5.1 will lock up completely as it clears the 
screen for the console if I have my display set to 1024x768 8-bit 
greyscale (haven't tried other resolutions in greyscale, might be all 
of them, not sure).  In 832x624 monochrome I get a rapidly scrolling 
repeating error message (don't have serial echo on for the console, 
didn't capture it) ad inifinitum.  In 832x624 16-bit color I get the 
console without errors but of course wscons doesn't work at that bit 
depth (what bit depth does wscons work at? only 1-bit?)  And stranger 
still, my Alps Glidepoint extended keyboard (with built-in 3-button 
touch pad) doesn't seem to be working in 1.5.1 (pressing keys does 
nothing){.  Here is my dmesg output from booting in 832x624 16-bit 
color:

[ preserving 418597 bytes of netbsd a.out symbol table ]
Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001
     The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
     The Regents of the University of California.  All rights reserved.

NetBSD 1.5.1 (GENERIC) #0: Wed Jul 11 15:55:34 CST 2001
     oster@piggy.oster.net:/u3/mac68k/src/sys/arch/mac68k/compile/GENERIC
Apple Macintosh Quadra 650  (68040)
cpu: delay factor 1067
total memory = 57344 KB
avail memory = 49272 KB
using 742 buffers containing 2968 KB of memory
mrg: 'Quadra/Centris ROMs' ROM glue, tracing off, debug off, silent traps
mrg: I/O map kludge for ROMs that use hardware addresses directly.
mainbus0 (root)
obio0 at mainbus0
esp0 at obio0 (quick): address 0x812000: NCR53C96, 16MHz, SCSI ID 7
scsibus0 at esp0: 8 targets, 8 luns per target
adb0 at obio0
asc0 at obio0: Apple Sound Chip
intvid0 at obio0 @ f9000080: DAFB video subsystem, monitor sense 0
intvid0: 832 x 624, 65536 color
macfb0 at intvid0
wsdisplay0 at macfb0: console (std, vt100 emulation)
sn0 at obio0: integrated Ethernet adapter
sn0: Ethernet address 08:00:07:1c:f3:78
iwm0 at obio0: Apple GCR floppy disk controller
iwm: Chip revision not supported (-77)
zsc0 at obio0 chip type 0
zsc0 channel 0: d_speed  57600 DCD clk 0 CTS clk 0
zstty0 at zsc0 channel 0
zsc0 channel 1: d_speed  57600 DCD clk 0 CTS clk 0
zstty1 at zsc0 channel 1
nubus0 at mainbus0
ae0 at nubus0 slot c: MacCon NuBus-A , 32KB memory
ae0: Ethernet address 00:00:94:60:29:8d
fpu0 at mainbus0 (mc68040)
scsibus0: waiting 2 seconds for devices to settle...
probe(esp0:0:0): max sync rate 4.03MB/s
sd0 at scsibus0 target 0 lun 0: <IBM, DCAS-32160, S65A> SCSI2 0/direct fixed
sd0: 2063 MB, 8188 cyl, 3 head, 172 sec, 512 bytes/sect x 4226725 sectors
probe(esp0:2:0): max sync rate 4.03MB/s
st0 at scsibus0 target 2 lun 0: <HP, C1533A, 9401> SCSI2 1/sequential removable
st0: drive empty
adb0 (direct, II series): 3 targets
aed0 at adb0 addr 0: ADB Event device
akbd0 at adb0 addr 2: extended keyboard
wskbd0 at akbd0: console keyboard, using wsdisplay0
ams0 at adb0 addr 3: Logitech MouseMan (non-EMP) mouse
wsmouse0 at ams0
akbd1 at adb0 addr 2: extended keyboard
wskbd1 at akbd1
boot device: sd0
root on sd0a dumps on sd0b
PRAM: 0x3b5b720a, macos_boottime: 0x3b5b7200.
root file system type: ffs
IP Filter: v3.4.9 initialized.  Default = pass all, Logging = disabled