Sorry if many posts have been created regarding the arena, i dont come on forums very often.
I use to play the arena day in day out, from time to time i check in and by the looks of it, it is still going at a snails pace!.
Can i suggest you guy make some kind of event inventables? for example, Easter event is coming up, you would have several new sets all using new components from the Easter event (which these componants are only available in the arena shop for 2 weeks during this event. this will encourage people to spend their tokens, and encourage people to play and earn more tokens again. i would suggest 4 or 5 events (arena) a year with new sets aimed at that current event, with the possibility of a new set or 2 each year.
I think every aspect of the game (pvp,gvg,se hunting etc.) needs an event like this of some sort to keep everyone happy.