I would like to say that Hail is currently ridiculous in this current metagame. I haven't played UU in ages. Yesterday, I made a Hail team. Now I'm #2 on the ladder. Froslass is actually a bitch and I'm quite okay to be using it. Practically guaranteed Spikes, excellent offensive capabilities, Blizz spam, Fighting immunity + Heracross switch in, Thunder Wave letting your slower guys rape shit? Froslass is kind of ridiculous. =(.
I dont think hail is that bad. The only problem I see is the aformentioned Frosslass, paralysis + Snow cloak isnt fun.That being said;
-Cobalion can utilise its high base speed, access too swords dance and sweep with close combat and iron head (or stone edge if youdont run iron head).
-Rotom H handles most of the other pokemon commonly seen on hail teams (nidoqueen/zapdos/suicune/hitmontop/arcanine) with proper prediction, whilst resisting blizzards thrown at it. Simply clicking overheat on a choice specs set is almost garunteed a pokemon death on the opponents team, if you arent running specs, pain split give it a form of recovery. Zapdos can do this with thunderbolt and heat wave, but has a weakness to ice which is undesireable.
-Chansey and snorlax wall hail all day long. Chansey does whatever it does and snorlax curses and laugh of your blizzards thanks to thick fat.
-Blastoise can run a set of; foresight/roar/rapid spin/move too garuntee removal of spikes and then roars froslass away.
-Registeel has STAB iron head and can lay down rocks.
-Suicune can calm mind up and rest.
-Victini can wreck some stuff with V-Create and U-turn too keep momentum. Scarfers outspeed mamoswine and frosslass, whilst banded ones lay down heavy damage even with U-turn
So hail isnt that bad, it has its flaws and pokes who can deal with it. I really don't like frosslass though, the faster it goes the better....