This thread for example:
Can this be done using the SDK?
Is there any difference in CS6 in that regard?
Short answer... No, not without a lot of work.
Long answer.... Yes, you could write an synthetic importer that knew how to process standardized subtitle files but it would be up to you to raster the font to a pixel plane - and provide a gui to configure that.
It would be coolest if there was a way to read the Adobe Story/OnLocation metadata and render the script to video that way.
As Rallymax mentioned, it is possible to directly integrate a subtitler plug-in into Premiere Pro using the synthetic/custom importer API.
In the thread you provided, it sounds like the Belle Nuit Subtitler provides a third-party option that can be brought into PPro using EDLs. Also, the Premiere Pro third-party plug-ins and tools page has been updated, and you can see that CPC and EZTitles also provide a subtitle workflow with Premiere Pro CS5.5.