Quickly counted off the top of my head but I don't think I have more than 15 binds that I actually use.
For some class the pruning was way over the top, but for shaman I was actually glad about it. I think before the totem change I was close to 55+ bindings; still got about 45 right now.
Regarding HotS - sure, I think it will be fun as a premade team of 5. But random? It is pure hell - you can't get ahead of the other team when you do well while you have 4 'tards on your own team. I joined relatively late in the beta and I just couldn't stand that you were so reliant on your team. At least in LoL I can do well in lane and then influence the game a bit even if the other people fed. Also no last hitting/items... sure, you got some more abilites to chose from, but it feels so boring and meaningless to stand in lane.
I don't think that it will be successful; not so much because I think that the game is shity, but rather because LoL/DotA are already so big. There are almost no new player available for that genre, everyone already played some other moba and will compare it with HotS, so it can only hope to get a fraction of those players.