That thread is just hysterical imo. They are mostly talking about the epic sets from rank 11+ and the epic weapons (rank 14). There are not going to be *that* many people that get up there anyway, and if they do they are likely to be very active pvp'ers. The way some people talk in the thread is that everyone can have access to this after a couple of weeks in the BG's.
What I like about this change is that you can take a break on pvp maybe for a week or two, lose rank but not lose equipment that you earned. I don't see such a big issue when we're talking about the blue sets (for which I only want 1-2 pieces max anyway). As above, there are not many that will see purple sets, and then they'll just stop pvp'ing?
On the caster vs melee argument, it's been going around for a while. And it's a fair one really, in that the really high end caster stuff does not make as big a difference as the melee stuff. I think they do need to boost the caster items a little, but caster v melee balance has always been a problem in any game of this type tbh. At the moment I don't see overwhelming evidence to say melee > casters, but I guess that might change as more people get better gear (would happen anyway regardless of this change).