They said there will be 12-20 perks per skill. And I think 50 perks could still be too much.
Which 5 skills do you plan to master? There probably isn't even a point in getting all skills for a perk, for example in 1-handed weapons you will have perks for swords, axes and maces. Unless you want to pick more than one, you'll probably spent only 5-6 perks here.
Once you made up your mind about your character's role, there's really not that much to decide. For example, I want my first character to be a shaman-like mage, with staves, illusion and enchanting magic. Even if I assume that Destruction would enhance my staff damage, and I want to get perks for my armor, that's only 4 skills. And I won't want to get all perks in all skills. Unless I change my mind and think that restoration or alteration are pretty neat and I want to use them too, I won't have to make a lot of choices.
I really think 50 perks will be more than enough.
A bit off topic: A thought just crossed my mind, which we probably can't answer right now because we know too little about the leveling system, but could there be a point where I got all the skills I want maxed, but didn't get to spend all 50 perks I want yet (meaning, I am below level 50)? That would mean I have to level other skills I don't want to use just to level up and get my perk points in other skills ...
I main a battlemage: one handed, block, armorer/crafting, destruction, alchemy, enchanting (which I may leave to the professionals, ie: enchanter NPC's, good place to use excess gold late game), those alone might max out my perks, not to mention the attribute effect perks I'd want like increased speed or jumping ability, or any random perks that might fit my character.