When you apply for CP you request areas and get placed. When you apply for a PI you are applying to a specific area/role.
I went from CP - PI in '08-'09. At the end of my PI I had the option to stay (on a temporary status), meaning that if there were budget cuts I'd be the first to go. So I went back to the parks instead and was statused in Merchandise - The Pirates League.
Some PIs lead into FT work, but some do not. It actually depends on the PI and how big the department is. When they post the PIs (probably around Aug-Sept), read through all of the different job descriptions and decide which ones you are qualified for. They ask that you only apply for three (many apply to more - I applied to 5).
Then you can ask on here who has experience with those specific PIs, is there opportunity to be hired on FT at the end.
I believe the majority of Management Interns go on to get statused. But most Managers were not interns first. It's more common to find a specific Line of Business (Merch, Attractions, Ent) and spend 2-5 years working your way up to Management.
If you're able to get a MI - DO IT! But if not, don't stress there are a lot of other avenues.
If you know specifically which area you want Management in now - try to make sure you get a CP in that area too! It's very hard to jump Lines of Businesses for advancement. So you'll want to get comfy in one area, network, show your skills, then put in for management when they hire (typically once every 12-18 months).
If you're interested in reading my path (it goes back to Dec. 2007) check out my blog (you need a livejournal account):
http://brennailya.livejournal.com/
