The next big jump in PDF may finally happen this year. The PDF association tells us that the spec for PDF 2.0 is “feature-complete” and will be available to the ISO PDF committee and members of the PDF Association in July. When this will turn into a public release still isn’t clear. A year ago the target was “mid-2016”; that seems unlikely now.
The specification will be ISO 32000-2. The current version of PDF, 1.7, is ISO 32000-1. More precisely, Adobe has published several extension levels to PDF 1.7. They’re a way of getting around having a version 1.8, which would be an admission that the ISO standard is outdated. Version 2.0 will get Adobe and ISO back in sync. Hopefully Adobe will publish the PDF spec for free, as it has in the past, so that it won’t be available just to people who pay for the ISO version. Currently an electronic copy of ISO 32000-1 costs 198 Swiss francs, or a bit more than $200.
What will the new features in PDF 2.0 be? The PDF Association talked about that almost a year ago. Laurel Brunner provided some information in 2013. A large part of the work is clarification rather than functionality. This doesn’t look like a major overhaul of the format, even though it’s the first bump in major version in its history. There will be enhancements to Tagged PDF, better color management, and a lot else, but apparently no structural changes or breaks in backward compatibility. More clarity about permitted data types would be nice; a lot of the bugs in the JHOVE PDF module have been due to my not realizing certain data types are permitted in certain constructions.
I’ll try to keep you up to date on further developments.
Mad File Format Science 
Will PDF 2.0 support ECC cryptography? I’m eagerly waiting for this… :)