Just for those who are interested, this is my personal assessment of where the characters in Street Fighter IV fall into the tier list: 
  

LordofUltima's SFIV Tiers

Top Tier

• Sagat
• Ryu
• Rufus
• Akuma
• Balrog

High Mid

• Zangief
• E. Honda
• Chun-Li
• Abel
• M. Bison
• Blanka

Low Mid

• C. Viper
• Guile
• Cammy    
• Seth
• Ken
• Gen
• Gouken
• Dhalsim

Low Tier

• Fei Long
• El Fuerte
• Dan 
• Sakura  
• Rose
• Vega