Ronald recently sent me this patch that he did in April.
> From: Ronald S. Bultje <rbultje@google.com>
> Date: Thu, 28 Apr 2011 17:30:15 -0700
> Subject: [PATCH] SSE2 optimizations for
> vp8_build_intra_predictors_mby{,_s}().
HD decode tests have shown a performance boost up to 1.5%,
depending on material.
Patch set 3: Fixed encoder crash.

Change-Id: Ie1fd1fa3dc750eec1a7a20bfa2decc079dcf48c8