With kernel configuration

# $NetBSD: GENERIC_USERMODE,v 1.1 2012/06/30 15:03:57 reinoud Exp $

include "arch/amd64/conf/GENERIC"
# it's probably worth testing in -current now if you want.  you'll need
# to enable these lines in your config:

nouveau*        at pci? dev ? function ?
nouveaufb*      at nouveaufbbus?

# and you might want to disable nouveau debug -- my console spews a really
# large amount, but only if it works ;)  you'll have to do this by editing
# files.nouveau to have this instead:

#no makeoptions nouveau
#makeoptions     nouveau CPPFLAGS+="-DCONFIG_NOUVEAU_DEBUG=0"
#makeoptions     nouveau CPPFLAGS+="-DCONFIG_NOUVEAU_DEBUG_DEFAULT=0"

Graphic Card is GTX-750 and dmesg may say:

nouveau0 at pci7 dev 0 function 0: vendor 10de product 1381 (rev. 0xa2)

The screen looks like
---------------------------
This machine has no serial console, so following part is hand-copied:
---------------------------

drm kern debug: nouveau T[     DRM] dec() == 3
drm kern debug: nouveau T[  DEVICE][nouveau0] use(-1) == 0
drm kern debug: nouveau T[  DEVICE][nouveau0] stopping ...
drm kern debug: nouveau T[  DEVICE][nouveau0] stopped
drm kern debug: nouveau T[     DRM] dec() == 2
drm kern debug: nouveau T[     DRM] fini running
drm kern debug: nouveau T[     DRM] 0xffffffff:0xffffffff fini children
drm kern debug: nouveau T[     DRM] 0xffffffff:0xffffffff fini running
drm kern debug: nouveau T[     DRM] use(-1) == 1
drm kern debug: nouveau T[     DRM] 0xffffffff:0xffffffff fini completed
drm kern debug: nouveau T[     DRM] fini completed with 0
drm kern debug: nouveau T[     DRM] dec() == 0
drm kern debug: nouveau T[     DRM] destroying
drm kern debug: nouveau T[  DEVICE][nouveau0] dec() == 1
drm kern debug: nouveau T[     DRM] 0xffffffff:0xffffffff destroy running
drm kern debug: nouveau T[     DRM] 0xffffffff:0xffffffff destroy completed
drm kern debug: nouveau T[     DRM] dec() == -1
nouveau0: unable to attach drm: 22
panic: cnopen: no console device
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff80114a75 cs 8 rflags 246 cr2 7f7ff6c0cce9 ilevel
0 rsp ffff0e811d985ac8
curlwp 0xfffffe811d863860 pid 2.1 lowest kstack 0xfffffef811d9822ce
Stopped in pid 2.1 (init) at netbsd: breakpoint+0x5: leave
db(3)>

dmesg with GENERIC is here: