I've always felt that TWF is a trap for rogues.
First is that it requires feats, which rogues are short on. Second is that it requires a rogue to get into melee range and that never seemed like a good idea for a class that has d6 hit dice, 3/4 BAB, usually limited to light armor, and no other class abilities that really directly help in combat.
If a rogue must go into melee I feel that rogue should use a reach weapon to put a little space between him and his foe(s).
While Pathfinder doesn't eliminate these problems it does help reduce them. Rogues for instance get a d8 for hit dice and the favoured class feature grants an extra hit point per level if you choose. Pathfinder also gives every character a feat at every odd level - which is nice. The 'Rogue Talents' are another source of feats or feat equivalent class features. At level 5 my proposed character has the following feats;
-Two-weapon fighting
-Skill focus (half-elf)
-Weapon finesse (rogue talent)
-Weapon focus
-Improved Initiative (rogue talent)
-Quickdraw
Weapon Focus is also available as a Rogue talent so if anyone can suggest a different feat to take at level 3 I'm all ears as I could take Weapon Focus as a talent at level 6.
Wanted to also offer a quick thanks for all the replies so far. There has been some good advice and lots of information to consider...