As far as evolution goes, I think claws (especially the way they are formed in cats) get in the way of complex hand dexterity. So, it makes sense for them to not be present/prominent in huminoid cats. It would be cool if in future games, that we could choose more than one type of Khajiit. There are sub-species that are less dexterous, but more powerful, so it could be that those types might have prominent claws.
hmm... i thought the more dexterous the cat, the better need for claws, the more powerful the cat, the lesser need for claws, speaking evolutionary.
If the cat is powerful, then its a good runner, can out run its prey and tackle it using muscle and its teeth as the weapon.
If the cat is dexterous, then its agility and quick reflex's compliment sharp claws as its best weapon.
To me, this Khajiit in the Skrym pic looks more like a power animal then an agile one. Sure hes probably more agile then most races besides the Woodelf, but still comes across as an animal that relies on power and has alot of stamina.
I think this Khajiit should have claws that are short, pointy but not sharp. And dont poke out to much, and dont extend out to much.
Though if i was to RP this Khajiit, I would probably choose an agility build over a power build... weird... seems more fun to be a sneaky thieving Khajiit cat burglar