Looking at sys_unlink(), the vp returned
by namei() is used to:
  1) Check for a mount point
  2) Check for write-blocking (new)
     using vn_start_write(). I believe
     this is in contemplation of LVM-based
     snapshots.
  3) Check leases for both the enclosing directory
     (ni_dvp) and the object itself (ni_vp).

Three thoughts:
  1) The VOP_LOOKUP() of the last component
     is needed for all these checks
  2) I'm uneasy with so many file system
     semantics being vested above the VOP
     layer; but
  3) I'd be more uneasy trying to keep pace
     with the evolving semantics below VOP_REMOVE()
     (and kindred) in all the file systems (including
     mine). Saving the VOP_LOOKUP() just isn't worth it.

Not enough of a case has been made for how eliminating
the VOP_LOOKUP() of the last component for dirops is a win.
A estimate of benefit might be helpful. For myself, I don't
see enough of a possible win to upset the VOP design.

Cheers,
	-gww