Re-create dependent views on ALTER TABLE ALTER COLUMN ... TYPE?

Hi Hackers,

This came up recently on general list (and I've just hit the same issue today):
http://www.postgresql.org/message-id/CAB7nPqTLmMn1LTb5WE0v0dO57iP0U73yKwzbZytAXDF1CAWLZg@mail.gmail.com

Why couldn't postgres re-create the dependent views automatically?  I
mean it knows which views depend on the altered column and keeps the
view definition, no?

Would a patch likely to be accepted?  How hard do you feel this might be
to implement?  Any caveat that defeats the purpose of such feature?

Thanks.
--
Alex