The combination of the change to stamina using less stat budget and a lot of pre-bc items having bad stat distribution is what made the jump big when bc came out. A T4 epic will have better overall stats, but a wotlk 70-72 green will likely have more specialized stats, but worse overall.

For example, Brooch of Unquenchable Fury from Kara has 24 sta, 21 int, 26dmg/heal, and 15 spell hit. A 70-72 wotlk green will probably have something like 30 int, 40 dmg/heal.