Kyogre won't become useless. I just hope that people use TWave + Lum Berry as it is quite a good set, because it somewhat cripples Latias and gives Palkia issues, who would otherwise take Water Spout with ease. I can't tell you how many times I have TWaved Latias as it switches in to take an expected Water Spout. Actually beats any Darkrai lead (though I have like 5 ways to check Darkrai on my team, despite running TWave + Lum) like ScarfOgre, but has other utility as well.
Rain is, of course, powerful like it has been. Kyurem-W can't counter Latias, as it takes a chunk from +0 Dragon Pulse, btw =) It is certainly a decent check, I agree.