Another mechanic which arcane can try to incorporate is the use of Priest's
Hymn of Hope - Spell - World of Warcraft
Both parts of the spell are beneficial especially the 15% increased mana.
It should allow us to increase the length of the 'burn phase' down to 25% mana. Then a /w macro to your friendly priest to channel HoH should increase maximum mana temporarily thus allowing evocation to bring you back to max mana.
Currently with raid buffed 50000 mana the burn phase is:
AB spam to 35% (about 17,500 mana)
Evocate for 60% of 50,000 (30,000 mana)
Back to 95% (47k ish mana)
With HoH at our disposal:
Again starting with 50,000 mana
AB spam to 25% (about 12,500 mana)
Hit macro asking for HoH - a power aura telling you that HoH is active is also v useful
Evocate for 60% of 57,500 (34,500)
Back to 95% (47k ish mana) PLUS any ticks of HoH which should actually get you back to 100%
This does of course rely on a priest willing to channel the spell, which in current ICC fights should be no problem. Wonder if any mages have experience of this.
We are currently trying to play with addons/frames so that both arcane mages can benefit from the HoH/ Obviously requires a little co ordination to ensure both are at around 25% mana before HoH is requested. Amazing how RNG procs can affect players during the burn phase - a few lucky procs of CC and you can be 10-15% mana ahead of a similarly geared mage.