Many thanks to cdmediasaver and Maite Sa for sharing clips on youtube and to World News Video and Tomo for tweeting links!!
The clip from cdmediasaver shows introduction of Keanu at the beginning of the press conference and footage of Keanu and some of the others answering questions. Maite Sa has shared video clips from the 47 Ronin press conference that ran on Japanese news shows. You can view them here, here and here.
Update: You can view another clip here.
Update X2: Thanks to akatumuri74 and PURIN n who have have posted clips on youtube from the press conference. They are here and here.
Note: All of the videos have press conference at the beginning and then they show the trailer. There is no additional coverage after the trailer. I will be updating as I find info.
Videos have been removed from youtube due to copyright issues or by owners.