Note: Sadly, because this post deals with the Season 4 PvP Ratings Requirement, I have the feeling that the comments will devolve into PvP vs PvE and miss my larger point.
The majority of Season 4 PvP gear will require the purchaser to have a personal rating of 1550 or higher. Even some of the gear obtainable through Battlegrounds will require Arena ratings. Many people, who thought PvP gear was too easily obtained for its quality, are happy about this, and many casual PvPers are unhappy.
It may surprise some of you--because I am in the camp which felt PvP gear was too easily obtained--but I believe that Rating Requirements are a bad idea.
The key is the concept of "Being On The Path" for endgame content. In nutshell, the number of people who reach the highest point of endgame is less important than the number of people who are working towards--and feel that they one day could achieve--that point.
For example, in PvE, the number of guilds in Sunwell does not matter. What really matters is the number of guilds who make it to Gruul and Magtheridon. Once a guild reaches Gruul and Magtheridon, they are "on the path" to Sunwell. Most of these guilds probably won't reach Sunwell before WotLK, but that doesn't matter. What matters is that they are steadily working on content, and feel that they could reach Sunwell eventually.
As long as a player is "on the path", everything is fine. The real crisis point are when people are unable to get on the path, or their progress on the path becomes completely blocked. I think it is less important to cater to the raiding guilds, and more important to help the guilds who are trying to become raiding guilds. To help the people who cannot get on the path at all.
This is why I feel Rating Requirements for Season 4 are a bad idea. If you are a casual PvPer, one who tries, but isn't really all that good, you've basically fallen off the path. And that is demoralizing.
In reality, of course, a casual PvPer is not likely to earn all the pieces of S4 before WotLK. But again, what is likely is not as important as what is possible. As long as you are on the path towards the end, that is the critical element.
If you look back at the last time I posted about PvP rewards, notice that I never outright denied a reward to a player. My suggestions made the process longer, but so long as a player kept at it, they would stay on the path towards Season 4.
The number of players who achieve the end is less important than the number of players who are on the path to the end. The number of players in Sunwell is less important than the number of players on the path to Sunwell. The number of players in Season 4 gear is less important than the number of players working towards Season 4 gear. With the advent of extensive Rating Requirements, the number of players on the path to Season 4 gear will drop drastically, and that is an unhealthy state for the PvP endgame.