If this happens, will MFS attempt to police the meet point
and force anyone who is currently providing "transit" to purchase
and user this "product"?
I don't see how they'd differentiate the traffic..
Will it change/worsen the performance of the heavier traffic
sites by "stealing" customers from the larger traffic sources, and
then dumping traffic upon those already overloaded circuits making
the HoLB problem all the worse?
If this happens I'd suggest everyone at the NAPs deploy some type of MAC-layer
filtering. It's far to easy (and seemingly common) for providers to forget to
set "next-hop-self" on NAP routes .. so what I foresee is providers selling
transit via the exchanges ...and then never seeing the traffic bound to
*their* unsuspecting peers.
Does anyone really care whether or not transit is sold over
the MFS meet points, and if so, what are the operation concerns?
I personally don't think it's a good idea, there are enough traffic related problems without "additional" transit-only connections.
Perhaps this is MFS's ploy to sell MAC-layer filtering 
-danny