I'm thinking Ninetales will drop, but I've seen a few sun teams (that use CharY AND Ninetales). The few sun teams I've run into run both CharY and Ninetales, but a lot of players run a non-weather team with CharY, and basically CharY sets up sun for itself without having the rest of the team abuse it. Makes sense as it lasts for what, 4 turns?
Blastoise is gonna be an excellent spinner. Last gen it was near the top in usage (many people felt undeservedly) and it had trouble getting passed Cofag. This gen, Cofag is gonna see a decrease since it relied quite a lot on the HP Fighting coverage, and ALSO M Blastoise has a way around it now. Also, we may see some ghosts join us in UU (one of the grasses? Imagine something like Jellicent coming down...) which may end up replacing Cofag as the most competent spin blockers but M Blastoise doesn't care about that.
Froslass is gonna be fine in UU. Last gen, it was just really annoying because spin blockers (I don't consider Chandelure a spin blocker, it has terrible switch in opportunities against every spinner) could just stay in on spinners all day long, so the "guaranteed 2 layers" that suicide Lass can set down would basically never ever leave the field. Suicide Lass is gonna be so much worse with Defog, and I think Bulky Lasses will actually need to be played intelligently
I've been using Rose in OU and I believe spikes is still really good. It's harder to use now because it's so much easier to blow away, but it's still not that hard to gain an advantage with them. I think that if you go with a spiker this gen, you should stay 1 hazard "ahead" of your opponent, try to identify their defogger and predict when they wanna come in. Force them to make a decision: either I defog and something nasty happens to my defogger, or i switch out of this horrible matchup but spikes remain on the field. For example, if I've already put something to sleep, Skarm has a free switch in to Rose. If Rose is on the field trying to say.... hit Togekiss with a SE hit, Skarm is gonna feel very comfy switching in. I know he wants spikes off the field, I suspect Skarm is his defogger so I'll switch into Heatran. He now has to decide between blowing away spikes while taking a Fire Blast, or switching in a resist, but continue to take spikes damage.
I see some people overblowing how dead spikes are. Yeah, spikes takes more intelligence to play now, but it's hardly dead. If you stay 1 hazard ahead, it means both players have "used up" the same number of turns on hazard related moves. But, having a spike advantage puts heavy pressure on your opponent to blow them away and you can use that one defog turn to do something really brutal