A lot of people want to see more differences in the races of the ES, and many want to see them fleshed out into more detail. Exactly how would you like to see the ten races changed for ES5 if/when it comes out? I've seen a lot of mention about attribute caps in order to make each race stand out, but personally, I don't know why a wood elf who dedicates his life to strength and fighting can't be as strong as a Nord. So, my input would be to let some races advance skills and attributes faster or slower than other races.
I would flesh races out by having their homes decorated in the style of their homeland with items from their homeland like foods, books, tapestries/rugs, clothing, trophies/artifacts, letters from/to homeland, weapons, armor, etc. That would make each NPC race unique to other races living in the same city/district.

We already have an official thread for http://www.gamesas.com/index.php?/topic/1145436-tes-v-ideas-and-suggestions-187/, you're welcome to repost this there