RE: Arp.
Yeah, I think the history of the redshift controversy is pretty well-tread at this point and there's probably no need to rehash it. I would agree, however, that Arp was generally well-received by other astronomers prior to questioning redshift =/= distance orthodoxy, at which point he was more-or-less black-balled.
Unfortunate, but, what can you do?
Anyway, back to the main article... The possible intrinsic component of Cepheid variables' blueshifts seems interesting.