I don't have a complete tier list yet, but Warrior is definitely the best class in arena right now. My last two runs with warrior have both been 7 win runs. The combination of strong items and prophecies from Strength and high stats creatures from Endurance are just too good.
EDIT: Unsure about classes tier list still, but currently it seems like greedy decks are the way to go, which leads me into thinking that pretty much any combination that includes Endurance is good.
Suggestions:
- Pick removal (this includes lethal creatures), big guys (especially guards and drains) and some (don't need all that much) early game. Strong items are also really good, especially cheap ones.
- Draft greedy control decks or crazy aggro decks. Midrange is pretty meh.
- I suggest not trying the whole Factotum thing, it's not worth it. Just pick the 3 mana 1/2 that gains lethal and the 2 mana 2/3 reflective automaton, the rest are pretty crappy.