Kindly use the below link for quick updates of Winter ’15 release
https://www.infallibletechie.com/2014/10/salesforcecom-winter-15-release-updates.html
Release Training:
http://www.salesforce.com/customer-resources/releases/winter15/release-training.jsp
Download the Release Notes here:
https://na1.salesforce.com/help/pdfs/en/salesforce_winter15_release_notes.pdf
You will have 3 attempts to pass the exam. There are 6 exam questions and the passing score is 67%.
We have to complete the online exam by February 27, 2015, prior to the next release (Spring ‘15).
For more info, visit http://certification.salesforce.com/schedules.
Cheers!!!