Nintendo of America on the 23rd of July filed/reapplied for a trademark regarding the Eternal Darkness franchise. It's a new filing and not a change to the prior trademark (serial number 77932350, filed in 2010). The application was entered in the Trademark Reporting and Monitoring System (TRAM) on the 26th of July.
Source:
http://tsdr.uspto.gov/documentviewer?caseId=sn86017853&docId=APP20130726072557#docIndex=0&page=1
However, the earlier trademark saw its fifth and final ITU Extension Approval in December last year, so this new application could simply be a continuing measure. Some minor differences exist in terms of Goods & Services between the two marks, but nothing important. Anyway, there's obviously some interest from Nintendo about Eternal Darkness as I doubt they would be making yet another filing for it without.
Hmm, maybe when Retro is done with Tropical Freeze...