Agility/Agility/Agility is a very, very good setup. It is what
Demetori,
Castrohpy and
I use in Preteen Dream Team. You "Could" run with Life-stealing in the mainhand, but it would be a complete waste imho.
I have a pair of gloves with 10 haste on them, and it IS nice - drops Wingblade down to a 1.75 second swing timer instead of 2.2 second. But remember that 15 agility is giving you like 5.8% crit and like 5.6% dodge....So is it really worth it? Since I got my Gloves of the Moon with 15 agi, I much prefer it over 10 haste.
So basically, 15 agi on both weapons, and 15 agility on gloves (but grab a pair with 10 haste, you might like it more.)