I was curious so I counted the cards. After "The Antlered Crown" we will have 360 different player cards counting the 49 heroes. So 311 non-hero cards. That's after 3+ years. Still, I am finally starting to feel that multiple "good decks" are now possible and so we are getting there.

100+ new cards per year is nothing to cry about. The TCGs that I played had similar numbers and I've always complained that they come out too fast. Granted, with TCGs you need a lot more time (and money) to actually collect all the cards, so the pace was even worse. Still, I have no complaints about the number of player cards we receive. The pace is too fast for casual players, just about right for semi-casual players, and apparently too slow for hardcore players. The only complaint I have is the lack of consistency in the release schedule.