Each hero may be equipped with one to four pieces of gear, depending on his advancement level. Does the his legendary gear count towards this limit?

As far as I know. Also keep in mind not only equipment limits but type limits as well. So if you have legendary armor you can't have any more armor at all no matter how many gear slots you have. At least that is my understanding. Like wise with accessories you can have 'any number' but only up to your max gear limit. Though it is also important to note from the dungeon deck that 'items' are not gear so you can end up with quite a few of those.

This is the official answer from the game developer Dane Beltrami

Oh really? Legendary Gear does not count towards your hero's gear limit?

Huh. That seems like a pretty big important rule that doesn't appear anywhere else. In fact, the Rules Reference seems to say otherwise, on page 10: "A hero can equip any number of his legendary gear cards following the normal equip restrictions..." Nowhere else in the Rules Reference, the Learn to Play booklet, or the official FAQ says anything to the contrary.

If this is a new rule / errata, so be it. But I don't see this Dana Beltrami guy listed anywhere in the game's credits.

Edit: Ug. I must have been really tired. No idea why I thought you said "does not". Sorry.

JohnGarrison1870: wait, what?

This is the official answer from the game developer Dane Beltrami

Legendary Gear does count toward your hero’s gear limit.

Thanks Dane for the quick answer!

Heh. Oops. I must have been really tired. Carry on, don't mind me...