I don't think Shaymin will be made uber. I can theorymon plenty of ways to beat it (Timid ScarfTran (which I use anyway) will always beat it and only have to be wary of ScarfMin's HP Grounds, Calm Zapdos can take Seed Flare, Air Slash, and HP Ground easily and PP stall with Substitute / Roost or just use HP Ice, Sassy Bronzong can take all three and Gyro Ball / Explode, Jirachi / Empoleon can pump themselves with Special Defense EVs (to survive the HP Ground) and OHKO this Shaymin with Ice Punch / Ice Beam, Pokemon with Ice Shard suddenly regain their significance, Pokemon like Aerodactyl / Jolteon become interesting since they outspeed and can hit with powerful Ice Fangs or Hidden Power Ices), but I "guess we'll see."
I am certainly excited to use it, however. Fuck those SubSeed sets that everyone and his mother is gooing their pants over...
I'm totally using Seed Flare, Air Slash, Hidden Power Ground, Whatever on a Choice Scarf / Choice Specs set (probably Scarf since I hate using Band / Specs and having to "predict").