All the MMO's nowadays have very little customization, so I doubt it. Everyone in WoW has the same gear sets that all look the same. Everyone in SWTOR looks the same. At least in DAoC you could dye all your armor/cloaks/weapons to any color you wanted. You could put guild emblems on your shields and cloaks. You could also make your character short, medium, or tall height. I'd like to see something like that implemented in ESO. And what's the deal with cloaks nowadays? No one puts them in anymore, and if they do it looks [censored]. The cloaks in DAoC looked awesome, and having one hooded dyed black made you look badass. Characters running around in a medieval fantasy setting without a cloak looks cheesy. So considering we probably wont see any personality or customization in those areas, I highly doubt we will see different shapes and sizes.
Really,i wouldn't say all MMO have little customization.
http://www.youtube.com/watch?v=g5i_mgF7Vas
http://www.youtube.com/watch?v=1WhOTrc5554
It really depends on how far the devs want to push it, personally i think it will be a strong feature in TESO.