Weavile has a number of problems though. Firstly 120 Attack is already a bit on the "average" side in Ubers, and having low base power on his attacks really sucks. As for Dragon-types the only things Weavile has a real chance of OHKOing is Rayquaza and Salamence. Dialga, Reshiram and Palkia aren't weak to Ice (Dialga needs to watch out for +2 Low Kick, I guess), Zekrom is bulky enough to take an Ice Punch or +2 Ice Shard (if it's Scarfed) and so is Dragon Arceus. Rayquaza frequently carries ExtremeSpeed these days, and with +2 priority, Ice Shard isn't helping you any more. All of them can OHKO Weavile in return, so Salamence is pretty much the only thing you're beating, and that is pretty damn rare already. Lati@s is a similar vein. I will give you Shaymin-S though, although Substitute probably foils you. In terms of Psychics, Lugia can take an LO Ice Punch and Whirlwind you out, and actually avoids getting 2HKOed by Night Slash if SR isn't up. Mewtwo is faster than you and will just kill Weavile before anything happens.
Even with those out of the way, Weavile has other problems. It is ridiculously frail, easy to wall and weak to SR. Even with its great offensive Ice-typing, its low attack power on its moves prevent it from breaking down any walls that are weak to it.
Whatevs sig. QC member for OU and Ubers, VM me for a look at your analysis. Just make sure it's good.
Also, if you want me to rate your team (OU/DW OU/Ubers), give me a VM. If I don't rate it, it's either 1) it's so shit it's too much trouble, 2) I'm busy, or 3) the team is fantastic and I have nothing I can suggest to you. You should be able to recognise which one.