RG Live WotLK 3.3.5a

http://talesofapriest.com/2010/02/24/hymn-of-hope-our-misunderstood-little-friend/

I love the Smell of Saronite in the Morning (General Vezax) was another good time – even a single priest channeling at the end provided enough mana for that last boost to knock him over (remember, Vezax is the fight that negates all mana regen mechanics).

http://elitistjerks.com/f77/t54626-wotlk_healing_discussion_v3_2_ulduar_coliseum/p28/

Weeks ago on Vezax ( assuming it hasn't been changed)I found that Hymn of Hope still grants you max mana for a short period of time even though it doesn't restore mana, so you can get a couple free heals while its up/ shields. I use inner focus basically off cd, the sooner I use it the sooner its up again( more free shields / heals).

http://www.threadmeters.com/wow/jGgz3A/How_to_get_mana_back_on_General_Vezax/

HoH gives you the 20% mana return that you lose.