DO NOT expect that your current job will let you transfer into the position. It's very unlikely that they will take a chance. Being a developer gives you an advantage but it's a matter of you putting in the time and effort to be a PM.
Also as PM, you will need to develop your soft skills to get the best effort from your team. PMs are responsible for getting a project completed on time but they don't have the ability to fire team members so you better be able to get the best from your team through other means than intimidation. I know PMs that blame the team when a project fails but the truth is that they are just as guilty if not more since a good manager should have been able to anticipate problems and manage the project to completion. Good luck.