The levels are split between 26 different heroes, some of whom are relatively low level, in particular characters who are awaiting their post-launch reworks. Overall it's 10 characters at level 60, 5 more inactive characters parked at level 50 or 52, and then a small handful of characters I actually consider active. There are a total of 2040 levels in game amongst the 34 released heroes, with a new 60-level hero added every month, so I'm not even half way to the total cap (especially since the higher levels go slower than the low levels do).
One odd bit of irony here is that I almost prefer to play when there is NOT an weekly event experience boost in effect. I have so many different ways to increase my exp gain that I don't have trouble getting my levels and I do sometimes have trouble not outleveling content. My "baseline" is over 150%, as I'm running at 123% synergy bonus plus 10% for Cyclops and 25% for an experience boon (which will run out in just over five days of /played time outside of hubs due to boon parties). On top of that, I have the following consumables:
- 16 of the common 50% exp boosts (32 hours total, I would "store" these by consuming all of them - which I've done with the 50% rare item find boosts - except that sometimes I want it to expire). The overwhelming majority of these come from quest rewards - three per character.
- Triple iridium 50% boosts (6 of these for a total of 12 hours, and these are comparatively more valuable because they stack with the regular boosts. Mine came from the most recent fortune cards)
- 100% rush bars (available in exp only - reasonably common and I have 9 of these - or triple iridium, where I have a whopping 14 due to the recent cards and promo codes, i.e. 23 hours of 100% bonus)
So that's where I am going into the game's touted 1st birthday. I'd say expectations - speculation runs anywhere from free G's for the cash shop to a surprise hero - are unrealistically high, but they have done a pretty impressive job with past events. Guess we'll know in a bit over a week.