Yes, ISO21500 standard was released in late 2012 and is being baselines in some countries already.
Another widely used standard is the Project Management Body of Knowledge (PMBOK®) Guide which is developed by the Project Management Institute (www.PMI.org). The PMBOK® Guide 5th edition was released late December 2012.
Unlike the ISO21500, PMI administers certification exams like The Project Management Professional (PMP®) and Certified Associate in Project Management (CAPM®) – there are others as well so have a look at the PMI website.
The 5th Edition exam will begin to be administered after 31 July 2013. After that date the exams will be based on the 5th edition. If you have had training based on the 4th Edition then make sure that you do take the exam before 31 July.
A simple answer: A standard is used as input to create your organisation’s methodology. For example the PMBOK® Guide has been used extensively by companies to create their own specific approaches to project management.
Yes, PRINCE2 is a methodology that is administered by the UK’s Association for Project Management. APM released the 6th edition of it’s Body of Knowledge in 2012, see: https://www.apm.org.uk/BOK6
You can become a PRINCE2 Practitioner by taking a certification exam given by many Accredited Training Organisations (ATOs). PRINCE2 has also a Foundation level exam.
Yes, there is the International Project Management Association (IPMA) which is the representative body of mainly European National Project Management Associations, see: https://ipma.ch/
IPMA also gives certifications at various levels that are baselined by their respective national Project Management Associations.