I don't think they can claim legal ownership to a date (2012)... Everyday objects and devices cannot be patented or trademarked, and dates would come under the same law.
Remember the MMX case which Intel lost with AMD? Also, Intel didn't choose 80586 / 586 for the sucessor to the 486, as they discovered that they couldn't trademark a number, so they chose of course Pentium.
I would be interested to follow any cases regards to 2012-related items.