This thread was at the time of GDR3, the announcement of 1520 and 1320 (first 3 column devices). Don't be panicked you'll get your third column for your windows phone in a week.but lumia 630 & 635 have 3 tile column in videos of windows phone 8.1 preview how is only for 1080p it need all higher lumias like 920+above series like as glance.
This looks quite nice on my 8x, but do agree that the icons are small but not something my fat fingers couldn't handle. Unless your hand is so unsteady im sure most could handle it as think of the size of the on screen keyboard, how tiny are they but we all manage don't we?
Based on what I read, the 3x5 Start Screen layout kicks in on 5" devices. Then, once a device reaches 6", the OS very subtly changes to display more info. Nothing major, but apps like emails or the People Hub will show more at once, resulting in less scrolling necessary. 5" devices only get to take advantage of the new Start Screen layout.
I watched a ton of video's before i purchased my 920 [came from iOS]in the beginning of may/july.
But still i think 720p screens could handle 6 columns