“Bring the player not the class” has been the tagline over on the official forums by Blizzard development staff for PvE/raiding class balance. With most buffs now raidwide versus party wide, and very few “gimmick” encounters needing certain classes, they have done a decent job of reaching this goal.
Where has this left the rogue class? Well, we’re about in the same place as we were in Sunwell raiding. Most guilds will bring 1-2 Rogues to fill their 15-18 DPS slots depending on the encounter. However, PuGs (pick up groups) abound for both the Tier 7 and Tier 8 10 and 25 man raid instances as well as the Vault of Archavon raid instance in the Lake Wintergrasp PvP zone. The new ease of PuG raiding has opened opportunites for many who may have never experienced this aspect of the game.
The following linked post lists some great resources that will help you tweak your Rogue DPS output and gameplay, so you can shine in any run you are invited to:
Newbie Rogue Pointers – WotLK Edition
http://forums.worldofwarcraft.com/thread.html?topicId=14133213611&sid=1
The original version of this thread was started on the EU Rogue forums and is credited at the end of the repost. Links above lead you to the same guide as reposted on the US Rogue forums. Take care in the official rogue forums though. Wandering around in there is about like wandering down a dark alley in Old Town.

side note – Rogues are now one of the least played classes in the game. Attrition due to the new DK hero class?
By: rogueraider on July 10, 2009
at 2:59 am
All classes took a hit from the DK wave… it’s possible, but the graphs suggest there’s something more to it..
By: Taeko on July 11, 2009
at 6:42 pm