Plenty of 'nids on DakkaDakka. I've only had the pleasure of getting wrecked by them in older editions, but lists have definitely shifted to Termagaunts and Tervigons. Genestealers and other melee still have a prominent place, and Swarmlords are still hellish nightmares to face. Other than adapting to a more shooty environment by adding their own shooting, that's about all I know.
Swarmlord is definitely a handful. Genestealers aren't that good anymore since they can't assault on the turn that they come in. The yrmgrl genestealers can, but I believe they are more expensive.
Our 'Nids player tends to run something along the following at 1500 points:
Tervigon x3
Termagrant brood x3
Flyrant or 2
Swarmlord
Gargoyles
Hive Guard (who can shoot 24" without LOS and ignoring cover unless it's granted by area terrain) x2 units of 2
When I played him last, ran the Flyrant instead of gargoyles. I'm pretty sure he puts adrenal glands on some units and takes the ability to select Catalyst with his Tervigons to have the option of giving himself Feel No Pain in a given round.
For the Swarmlord, he rolls on the Biomancy table, since you get four powers, until he gets Iron Arm, though Endurance and the power that gives you more attacks is nice. If he gets Iron Arm, he then goes to whatever discipline gives you Invisibility (telepathy, I believe). Giving the Swarmlord +d3 toughness, Eternal Warrior, and a cover save through the use of both of those powers is pretty nasty.