As a team lead, I'll be honest with you. If there is an open position and it hasn't been filled yet after a few weeks, its because they already have a plan in place. If they were going to promote you to the spot that is currently avaliable, they've would've already told you. If you aren't currently on the bench, there is a very high chance that you will not get promoted right now. They are creating a developmental plan for you so you can showcase your skill and drive. You will have to pretty much prove to them that you have the full potential so that you can be put on the bench, so when a spot opens up you will already have the tools and will be fully prepared. So don't take it personally when they announce someone else. Be thankful that they are willing to develop you and work hard at it.