There are indeed a few thorny issues with this approach; the largest issue is
that all connectivity becomes DNS-dependent and raw IP addresses (from both
the inside and outside) become virtually useless. Running servers behind
this scheme, while doable, is difficult.
When an ISP's caching name servers ignore your 3600 TTL and substitute an
86400 TTL you end up disconnected for ~12 hours instead of ~30 minutes-
That's unacceptable for a almost any company willing to go through the
trouble of getting an ASN.
-Don
