I voted Abomasnow because I think in general people know less about it than anything else listed. Mew may be unpredictable and can do a lot, but it's already been used quite a bit in Ubers. Baton Pass and the Lead sets have all been explored, so I guess the only thing to experiment with it would be maybe an offensive set (which would likely be outclassed in most aspects). On the other hand, Abomasnow is a really unrated/underused Poke in Ubers. I was frustrated the other day to have not only my Kyogre walled by Aboma, but my Support Groudon struggling to do anything to it, indicating how versatile of a Pokemon Abomasnow can be. Hail is also very cool, and seeing as I've never tried it before, I think these research weeks would give everyone a good chance to see how good it is.