Certifications are a great way to verify and document your skills. To help you certify your Office 365 skills we're releasing two exams soon (expected in april 2012)
Exam 70-323: Administering Office 365 intended for IT professionals who administer Microsoft Office 365 in an environment that may include Microsoft Exchange, Microsoft Lync, and/or Microsoft SharePoint - link
Exam 70-321: Deploying Office 365 intended for consultants and IT professionals who plan and implement Office 365. This includes migrations to Office 365 (simple and hybrid deployments) - link
Passing these two exams will give you two certifications:
Currently no preparation materials have been published, but a good starting point would be the virtual labs on the (great) new Office 365 TechCenter, your new one-stop for all the technical info on Office 365
UPDATE July 2012. Recently two on-demand online preparation courses has been published:
UPDATE2 August 2012. New “Exam 74-324: Administering Office 365 for Small Business” introduced
Note: as a Microsoft Partner you might want to take a look at the Office 365 Practice Accelerator - a great help in building a practice around Office 365. 4x4 hours training available for you now!