For me they never were dark elves. Appearance aside, they feel more like wood elves. They are archers and druids who live with treants and so on. Priests of Elune are quite interesting but they still fit. Also, I wouldn't count ancient highborne as night elves. They have similar(10000 years can lead to some minor changes) biology but they are culturally different. They split, like in Tolkien, to high elves(nightborne, Shen'dralar, blood elves) and wood elves, our long vigil group.
For dark elf archetype, nagas are the best. They are fallen elves who live in darkness and plot against eachother. They worship dark god and serve ambitious queen who holds grudges against other elves. The difference is that they replaced underground with water and added fish parts to their appearance. Also, we can't call them purely evil, some of them are tragic people who were so unlucky to drown with Azshara.
Prattchet gone even further and made an orc philosopher.Orcs and blood elves (also void elves) were another twist I liked. Orcs were cunning, intelligent, whiles maintaining their savage and brutish edge.. but they weren't dumb like in many portrayals, and Warcraft and LotR were the only two fantasy worlds were orcs actually felt dangerous, but Warcraft the only one were they were redeemable and again had this diverse range and reach, not just limited to "the savage warrior ME SMASH" portrayal. However the fact that is how orcs are perceived in other fantasies, plays out quite well, as this view of orcs is often held by arrogant races like elves and humans, yet is far from the truth.
I liked how high elves made by Blizzard weren't just bland lawful good elves. I like theme of civilised races that are more Macciavellian. They are also interesting due to internal splits. My only issue is that Blizzard makes them slowly lost their uniqueness, as warlocks were replaced by paladins and now nightborne make them leave arcane market aswell.Blood elves exploring the magical addiction started in the night elf story and turning out to be less than the upstanding morally perfect and virtuous high elf was also interesting. I definitely found Tolkein's high elves interesting and how he managed to portray them as he described them, an impressive feat I have now learned as nearly every other fantasy has failed to get immortality/long lived or highly intelligent races (as they describe portrayed). The blood elves however were flawed elves morally, but with the cunning high intelligence of the race, keeping their beautiful appearance, but being quite the opposite (in many cases) on the inside, was great, they offered both the hope of returning to their nobler past yet not and offering a more devious feel to the blood elves without going the all out evil/crazy that competing elven groups (like dark elves usually have).
I don't think night elves are more intelligent than blood elves. I might be wrong but I get that perception from roles these races play. Blood elves are scholars while night elves are devouts and warriors.My only gripe is actually not really with them, but the lack of the night elven group being out paced by the blood elves because it doesn't fit the original lore, night elves are supposed to be by default superior in every aspect, magical aptitude, intelligence, longevity, stature - but they aren't as ambitious as the blood elves and are crippled by shame and guilt because of the sundering - yet they were initially shown to be sterner and more commanding only to have them fad e to nothing which I have always felt isn't a good move, because of how popular the high elf is, you always need to make your dark/night elf one step ahead to compete, and I felt that the night elves have the racial background to provide that, but it isn't utilised in wow at all and that's because of gameplay facors.