Question about peering

Sat Apr 7 22:35:15 UTC 2012

On Sat, Apr 07, 2012 at 06:16:30PM -0400, Robert E. Seastrom wrote:
> Sometimes making the AS path as short as possible makes a lot of sense
> (e.g. when trying to get an anycast network to do the right thing),
> but assumptions that peering results in lower costs are less true
> every day.

I keep reading people say that.  But wouldn't the same forces that push 
down the per-megabit cost of transit also push down the per-megabit
cost of peering?  