a Cali sticker will work till July 1, 2013... and after really. Escpecially if you don't ride in NV how are they going to know until you sell it.
You are NOT required to get a NV title for an OHV purchased before July 1, 2012.
You ARE required to get the registration sticker, but again, NV has to know you even own the OHV and/or see it riden in NV. I still think getting the NV tag is easier and a little cheaper, but NV is going to have a real tough time tracking down all OHVs owned by Nevadens. Plus are they really going to spend a bunch of time tracking people down for stickers? Now if the bike is sold in Nevada, and has never been registered before before they might figure it out, and the new owner would have to get a title, theortically, so they would have to register as well.
Overall, it's just easier to get the NV stuff.