I already outlined this for you - I can't force myself to watch all the videos again just to find something you desire proof for. Want to get the proof? Sort through it yourself.
I will continue to speak that after 50 you don't get perks, as I have - personally, through an interview, heard Todd Howard say so. So have others. You have proven you have the list of interviews, go to it.
I'm not going to waste my time - videos are no search friendly playground. If there are transcripts of every single video there, let me know. Ctrl-F is a lot better than listening - likely for the third time - to how dragons aren't scripted, and my computer can't handle scanning through the video (Vista on 1 gig of ram and a wireless connection(wireless from here to the ISP, horrible speeds) = watch the video from start to finish or Firefox "stops responding").
Don't believe me (and other posters who magically agree to what I've heard)? Fine. You have your options. Go watch the videos, find me a transcript for all videos, or just ignore my posts when I post that fact.
The thing is, I've already watched all of those videos on mr frosty's link (every single one), and read probably every single Skyrim article ever posted on this forum, and I have probably even read every thread on this forum where someone claims that perks stop at level 50.
Nowhere have I ever seen, heard, or read any mention by one of the devs that perks stop at level 50. None of those threads on this forum claiming perks stop at 50 have ever listed an official source, AFAIK.
However, if you ask me where did I hear that there is racism in Skyrim, for example, or where did we first learn that there is purportedly no spellcasting in Skyrim, or which source mentioned that there are quests involving Aedra and the planes of Oblivion, I can tell you exactly which interview mentioned that. Any detail that I currently know from Skryim, I can have at least some general idea where I learned that information.
Especially the video interviews - there are really only a small number of videos, not dozens and dozens of interviews. It seems remarkable that you recall this was in a video interview, but you have not even the slightest idea of who Todd was talking to or which interview it was. In all of the articles and interviews I have seen where Todd mentions that Skyrim is a "level 1-50" game as opposed to a "1-25" game, or that it has a "soft cap" at the mathematical limit (70-80) as opposed to a "hard cap," he has never mentioned that perks suddenly stop at level 50.
It might be that you are correct; however, why is it that we have never seen any threads on this forum that list a source for this rumor of perks suddenly stopping part way through the game?